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Iranian Journal of Polymer Science and Technology (10163255) 36(5)pp. 457-485
Perovskite solar cells (PSCs), despite the stability challenges they face, have made significant progress. It is predicted that this trend will continue due to the progress in composite engineering and the materials that make up the layers. It is expected to continue to achieve high performance and long-term stability in these cells. One of the key components and layers in PSCs is “electron transporting material” (ETM), playing a crucial role in electron transfer, extraction, and cell efficiency. ETMs are categorized into various types based on their constituent materials, including inorganic, organic, and polymer-based ETMs. Polymeric ETMs are of particular importance due to their unique properties and considering the limitations in other types of ETMs. Fullerene derivatives, which are organic ETMs, lack adequate electron mobility and solubility. However, in polymeric ETMs, the ability to connect different functional groups to their central core creates significant changes in the photovoltaic parameters of the cell. By choosing polymeric ETMs, potential advantages such as high electron mobility, easy purification, suitable solubility for processing during layer deposition, and desirable stability can be achieved. Polymeric ETMs with various central cores such as naphthalenediimide (NDI), perylenediimide (PDI), and bithiopheneimide (BTI) have been widely used in reverse PSCs due to their high electron mobility and the absence of additives. Among them, the highest efficiency (20.43%) relates to a cell containing the PDI-core polymer PPDIN6. Additionally, researchers use n-type polymers to modify, create effective interlayer connections, and improve the photovoltaic parameters of reverse PSCs. This review article highlights that the selection of polymeric ETMs along with specific central cores can lead to meaningful changes, resulting in desirable performance and stability in PSCs.
Li, X. ,
Ahangar, H. ,
Yang, S. ,
Huang, J. ,
Sheibani, E. ,
Kuklin, A.V. ,
Luo, X. ,
Ghahfarokhi, F.A. ,
Wei, C. ,
Ågren, H. ACS Nano (19360851) 19(7)pp. 6784-6794
Organic hole-transporting materials (HTMs) with high hole mobility and a defect passivating ability are critical for improving the performance and stability of perovskite optoelectronics, including perovskite quantum dot light-emitting diodes (Pe-QLEDs) and perovskite solar cells. In this study, we designed two small-molecule HTMs, termed X13 and X15, incorporating the methylthio group (SMe) as defect-passivating sites to enhance the interaction between HTMs and the perovskite layer for Pe-QLED applications. Our study highlights that X15, featuring SMe groups at the para-position of the carbazole unit, demonstrates a strong interaction and superior passivation effects with perovskite quantum dots. Consequently, Pe-QLEDs (0.09 cm2) incorporating X15 as the HTM achieve a maximum external quantum efficiency (EQE) of 22.89%. Moreover, employing X15 in large-area Pe-QLEDs (1 cm2) yields an EQE of 21.10% with uniform light emission, surpassing the PTAA-based devices (EQE ∼ 15.03%). Our finding provides crucial insights into the molecular design of defect-passivating small-molecule HTMs for perovskite light-emitting diodes and related optoelectronic devices. © 2025 American Chemical Society.
Zhou, G. ,
Hashemi, F. ,
Ding, C. ,
Luo, X. ,
Zhang, L. ,
Sheibani, E. ,
Luo, Q. ,
Jumabekov, A.N. ,
Österbacka, R. ,
Xu, B. Nanomaterials (20794991) 15(13)
In recent years, inverted perovskite solar cells (PSCs) have garnered widespread attention due to their high compatibility, excellent stability, and potential for low-temperature manufacturing. However, most of the current research has primarily focused on the surface passivation of perovskite. In contrast, the buried interface significantly influences the crystal growth quality of perovskite, but it is difficult to effectively control, leading to relatively slow research progress. To address the issue of poor interfacial contact between the hole transport-layer nickel oxide (NiOX) and the perovskite, we introduced a conjugated self-assembled monolayer (SAM), 4,4′-[(4-(3,6-dimethoxy-9H-carbazole)triphenylamine)]diphenylacetic acid (XS21), which features triphenylamine dicarboxylate groups. For comparison, we also employed the widely studied phosphonic acid-based SAM, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl] phosphonic acid (MeO-2PACz). A systematic investigation was carried out to evaluate the influence of these SAMs on the performance and stability of inverted PSCs. The results show that both XS21 and MeO-2PACz significantly enhanced the crystallinity of the perovskite layer, reduced defect densities, and suppressed non-radiative recombination. These improvements led to more efficient hole extraction and transport at the buried interface. Consequently, inverted PSCs incorporating XS21 and MeO-2PACz achieved impressive power-conversion efficiencies (PCEs) of 21.43% and 22.43%, respectively, along with marked enhancements in operational stability. © 2025 by the authors.
Chu, W. ,
Yang, H. ,
Lei, X. ,
Yan, N. ,
Ghahfarokhi, F.A. ,
Guo, Y. ,
Guan, Z. ,
Fang, Z. ,
Sheibani, E. ,
Cheng, Y. Chemical Engineering Journal (13858947) 519
Self-assembled monolayers (SAMs) have been successfully designed and adopted in the field of inverted perovskite solar cells (PSCs), in which molecular introduction could optimize the buried interface of perovskite films. Compared to the typical [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), the multifunctional SAMs with methylthio (MeS) group were introduced to simultaneously modulate perovskite crystallization kinetics and passivate the interface defects. Using in-situ photoluminescence (PL) spectroscopy, it is well demonstrated that the strong interaction between MeS and uncoordinated Pb2+ significantly retards the nucleation kinetics and promotes grain ripening, leading to 12% increase of grain size at the buried interface. Meanwhile, the carrier lifetime measured by transient absorption (TA) spectroscopy also increased from 711.97 ps to 1832.72 ps. As a result, the target devices exhibit an effective power conversion efficiency (PCE) promotion from 22.10% to 25.21%, accompanied by an enhanced open-circuit voltage (VOC) from 1.08 to 1.17 V. © 2025 Elsevier B.V.
Yang, S. ,
Moslempoor, M. ,
Li, X. ,
Kuklin, A.V. ,
Luo, X. ,
Sheibani, E. ,
Wei, C. ,
Ågren, H. ,
Baryshnikov, G. ,
Xu, B. Chemical Engineering Journal (13858947) 500
Organic hole-transporting materials (HTMs) play critical roles in the performances and stability of perovskite quantum dot light-emitting diodes (Pe-QLEDs). Ideal HTMs for Pe-QLEDs must satisfy three key principles: high hole mobility, energy level alignment, and interface passivation. However, the combined effects of these factors on Pe-QLED performances have not been thoroughly understood. In this study, we tailor-made three carbazole-based dendritic small-molecule HTMs, named X51, X52, and X53, each with distinct optical and physical properties for application in Pe-QLEDs. Our findings revealed that X51 exhibited a highest hole mobility but had a high energy barrier, while X53 demonstrated the best interface passivation effect but suffered from the lowest hole mobility. In contrast, the X52 achieved the best balance of properties, resulting in Pe-QLEDs with the highest external quantum efficiency (EQE) of 23.78% (the highest reported for small molecule HTM-based Pe-QLEDs to date), significantly outperforming devices based on X51 (5.52%) and X53 (12.73%). This outcome, akin to the “bucket effect”, underscores the importance of balancing multiple properties in the design of small-molecule HTMs. These results not only present a high-performance small-molecule HTM but also provide crucial insights for comprehensively considering multiple design factors in the HTM development. © 2024 Elsevier B.V.
Yang, X. ,
Luo, X. ,
Guo, Y. ,
Zhao, D. ,
Sheibani, E. ,
Xu, B. Journal of Materials Chemistry C (20507526) 12(47)pp. 18952-18971
Metal halide perovskites have emerged as promising semiconductors for next-generation optoelectronics, particularly due to their solution processability and exceptional semiconductor properties. Over the past few decades, the performance of perovskite-based solar cells (PSCs) and light-emitting diodes (PeLEDs) has seen rapid improvements. However, the operational stability of these perovskite optoelectronic devices remains a significant challenge. One critical factor influencing both efficiency and stability is the choice of hole-transporting materials (HTMs). Recently, there has been a growing focus on cross-linkable HTMs as a means to enhance device stability. This review systematically summarizes the role of cross-linkable HTMs in PSCs and PeLEDs, emphasizing their material advantages, design principles, physical properties, and advancements in device performance. Special attention is given to the impact of cross-linkable HTMs on device interfaces and overall stability. We conclude by discussing the future challenges that must be addressed to further advance the application of cross-linkable HTMs in both PSCs and PeLEDs. © 2024 The Royal Society of Chemistry.
Deng, J. ,
Ahangar, H. ,
Xiao, Y. ,
Luo, Y. ,
Cai, X. ,
Li, Y. ,
Wu, D. ,
Yang, L. ,
Sheibani, E. ,
Zhang, J. Advanced Functional Materials (1616301X) 34(4)
Considering the high surface defects of polycrystalline perovskite, chemical passivation is effective in reducing defects-associated carrier losses. However, challenges remain in promoting passivation effects without compromising the carrier-extraction yield at the perovskite interfaces. In this work, interlayer molecules functionalized with different side groups are rationally designed to investigate the correlation between defect-passivation strength and interfacial carrier dynamics. It is revealed that Cl-grafted molecules impose destructive effects on the perovskite structure due to its lower electronegativity and mismatched spatial configuration. The introduction of cyanide (CN) as a side group in molecules also leads to perovskite deformation and unfavorable hole collection. After the molecular optimization, the incorporation of carbonyl (C═O) as the side group (TPA─O) simultaneously promotes the carrier-collection yield as well as sufficient defect passivation. As a consequence, the devices based on TPA─O yield a champion PCE of 23.25%, along with remarkable stability by remaining above 88.5% of initial performance after 2544 h storage in the air. Furthermore, this interlayer based on TAP─O enables flexible devices to achieve a high efficiency of 21.81% and promising mechanical stability. This work paves the way for further improving the performance of perovskite solar cells. © 2023 Wiley-VCH GmbH.
Li, X. ,
Haghshenas, M. ,
Wang, L. ,
Huang, J. ,
Sheibani, E. ,
Yuan, S. ,
Luo, X. ,
Chen, X. ,
Wei, C. ,
Xiang, H. ACS Energy Letters (23808195) 8(3)pp. 1445-1454
Hole-transporting materials (HTMs) play critical roles in the device performance and stability of perovskite quantum dot light-emitting diodes (Pe-QLEDs). However, the development of small-molecule HTMs for achieving high-performance Pe-QLEDs has proven to be very challenging because of their low hole mobility and poor solvent resistance. Herein, we tailor-made a multifunctional small-molecule HTM, termed X10, with methoxy as the substituents, for application in Pe-QLEDs. X10 features high hole mobility, good film-forming ability, and strong solvent resistance ability as well as defect passivation effect. Subsequently, Pe-QLEDs employing X10 as HTM presented a promising external quantum efficiency (EQE) of 20.18%, which is 7-fold higher than that of the reference HTM-TCTA-based ones (EQE ≈ 2.88%). To the best of our knowledge, this is the first case in which a small-molecule HTM displays a high EQE over 20% in Pe-QLEDs. Our work provides important guidance for the rational design of multifunctional small-molecule HTMs for high-performance Pe-QLEDs. © 2023 American Chemical Society.
Sheibani, E. ,
Hosseini, A. ,
Sobhani-nasab, A. ,
Adib, K. ,
Ganjali, M.R. ,
Pourmortazavi, S.M. ,
Ahmadi, F. ,
Marzi khosrowshahi, E. ,
Mirsadeghi, S. ,
Rahimi-nasrabadi, M. Critical Reviews in Food Science and Nutrition (10408398) 63(16)pp. 2626-2653
Preparing samples for analyses is perhaps the most important part to analyses. The varied functional groups present on the surface of biopolymers bestow them appropriate adsorption properties. Properties like biocompatibility, biodegradability, presence of different surface functional group, high porosity, considerable absorption capacity for water, the potential for modification, etc. turn biopolymers to promising candidates for varied applications. In addition, one of the most important parts of determination of an analyte in a matrix is sample preparation step and the efficiency of this step in solid phase extraction methods is largely dependent on the type of adsorbent used. Due to the unique properties of biopolymers they are considered an appropriate choice for using as sorbent in sample preparation methods that use from a solid adsorbent. Many review articles have been published on the application of diverse adsorbents in sample preparation methods, however despite the numerous advantages of biopolymers mentioned; review articles in this field are very few. Thus, in this paper we review the reports in different areas of sample preparation that use polysaccharides-based biopolymers as sorbents for extraction and determination of diverse organic and inorganic analytes. © 2021 Taylor & Francis Group, LLC.
Iranian Journal of Polymer Science and Technology (10163255) 36(2)pp. 107-132
In recent years, the performance of perovskite solar cells (PSCs) has made a significant growth of about 25.5%. Nonetheless, the long-term stability of these cells for industrial production is still a major concern. One of the important reasons for the instability and degradation of the perovskite layer is its sensitivity toward moisture, oxygen, lack of resistance to ultraviolet light, electric fields, and temperature. In this context, hole-transporting materials (HTMs) play a key role in the construction of a stable inverted perovskite solar cell, including regulating the growth and crystallization of the perovskite and creating a water-repellent surface with a suitable structure. Naturally, the function of a hole-transporting layer (HTL) depends on the type of perovskite solar cell configuration, and it is discussed in detail in the relevant section. In recent decades, researchers have focused on developing stable HTMs based on additive and non-additive semi-conducting polymers. Polymers have unique properties such as adjustable molecular weight, easier mobility of the hole compared to organic compounds, and suitable conductivity under additive-free conditions for 3D printing applications at an industrial scale. In addition, the cost-effectiveness of synthesis steps and potential interlayer displacement during the manufacturing process has made attraction and innovations in this area. Therefore, this article evaluates and analyzes the performance and mechanism of hole-transporting layers based on p-type semi-conducting polymers and the effect of various component structures of polymer systems on the inverse perovskite solar cell system. Polymers such as, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), poly[bis(4phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and (poly(3-hexylthiophene) (P3HT) have received most of the research and experimentation, with PTAA being the most desirable and efficient option, reaching over 25% efficiency. © 2023 Iran Polymer Society. All rights reserved.
Molina, D. ,
Sheibani, E. ,
Yang, B. ,
Mohammadi, H. ,
Ghiasabadi, M. ,
Xu, B. ,
Suo, J. ,
Carlsen, B. ,
Vlachopoulos, N. ,
Zakeeruddin, S.M. ACS Applied Energy Materials (25740962) 5(3)pp. 3156-3165
In this work, we describe a new class of non-fused 3D asymmetric compounds (named 1, 2, 3, and 4) as low-cost organic hole-transporting materials (HTMs) for perovskite solar cells (PSCs). The fundamental understanding of the influence of the methylthio and methoxy group substitutions on the fluorene moiety has been analyzed, as well as the position of methoxy groups in the aromatic rings of triphenylamine pending groups (para or meta). Experimental results demonstrate that the position of the methoxy group in the triphenylamine pending group influences decisively the thermal properties and the amplitude of the electronic bandgap, hydrophobicity, film formation, and thermal stress stability. The presence of methylthio or methoxyl substituents in the 2,7-positions of the fluorene moiety mainly affects the electrochemical properties, hole mobility, and morphology of the hole-transporting layer (HTL). Thus, maxima sunlight-to-electricity power conversion efficiencies (PCEs) of 17.7 and 17.8% have been obtained in PSCs with methoxy groups in the fluorene moieties (1 and 3), respectively. Consequently, compound 1-based PSCs exhibit a better stability than the other three materials and the standard HTM-spiro-OMeTAD-based devices. © 2022 American Chemical Society. All rights reserved.
Vahabi, A.H. ,
Norouzi, F. ,
Sheibani, E. ,
Rahimi-nasrabadi, M. Coordination Chemistry Reviews (00108545) 445
UiO based metal-organic frameworks (MOFs) have attracted much attention of many scientists among the large family of Zirconium MOFs. UiO-series including UiO-66, -67 and -68 which possesses high stability, tunability, porosity, and functions, are rapidly extending field in metal-organic frameworks since 2008. This progress in this family of MOFs, extended to the ability of linkers to be functionalized and led to generate new crystalline materials with desired properties and applications. This review presents comprehensively all of the reported functionalized and unfunctionalized UiO-67 MOFs in terms of structural classification. The overall framework of UiO- based MOF constructed from three different linkers including 4,4′-biphenyl dicarboxylic acid (bpdc), 2,2′-bipyridine-5,5′-dicarboxylic acid (bipydc) and 2-phenylpyridine-5,4′-dicarboxylic acid (ppydc). Also, the metalation of these linkers within MOFs investigated. Furthermore, a brief study on the application of the UiO-67-based MOFs was conducted. © 2021 Elsevier B.V.
Solar RRL (2367198X) 4(12)
Perovskite solar cells (PSCs) with advantages of exceptional photovoltaic performance and facile solution-processed fabrication have shown great potential in future scalable application. After about a decade of rapid development, this new PSCs technology demonstrates over 25% efficiency, a comparable performance with traditional silicon solar cells. Further, the development of PSCs in the direction of scalable production still highly relies on designing innovative materials with low cost and high efficiency. Recently, a great number of functional organic molecules as hole transport materials (HTMs) have been designed, synthesized, and studied in PSCs, including molecules with planar structure, 3D geometry, or different core units. Discovering the correlation between their chemical structures and physicochemical properties plays a fundamental role in supervising future molecular design and synthesis. Herein, recent advances in organic molecular HTMs with various structures in typical and reverse PSCs device configuration are summarized, including doped and doping-free materials. By evaluating the structural modification and analyzing their effects on photovoltaic performance, the goal is to generate universal strategies for preparing low-cost and efficient HTMs, paving the way for future scalable application of PSCs. © 2020 Wiley-VCH GmbH
Sheibani, E. ,
Heydari, M. ,
Ahangar, H. ,
Mohammadi, H. ,
Fard, H.T. ,
Taghavinia, N. ,
Samadpour, M. ,
Tajabadi, F. Solar Energy (0038092X) 189pp. 404-411
Carbazole compounds are p-type hole-transporting materials (HTMs) useful for perovskite solar cells (PSCs). In this work, we developed a new class of carbazol based HTMs; non-fused 3-D asymmetric structures (S14 and S12) as HTM of PSCs. To the best of our knowledge, there is no report on non-fused HTMs with a high glass transition temperature (Tg = 165 °C), which reduces crystallization and suppresses grain boundaries in glassy film, resulting in long-term durability. Experimental results show that tuning the carbazole moiety in S14 structure has a constructive influence on geometrical alignment, hole mobility, hydrophobicity, stability as well as efficiency. The resultant power conversion efficiency (PCE) of devices were 15.31% and 11.85% for S14 and S12, respectively. Cell efficiency decreases during the first day for all devices. But after this time, the cell efficiency of the device fabricated with S14 remains constant until 1000 h at atmospheric condition without encapsulation while for devices fabricated by S12 and Spiro-OMeTAD the cell efficiency decreases to 75% and 69%. © 2019
Zhang, J. ,
Hao, Y. ,
Yang, L. ,
Mohammadi, H. ,
Vlachopoulos, N. ,
Sun, L. ,
Hagfeldt, A. ,
Sheibani, E. Electrochimica Acta (00134686) 300pp. 482-488
A new conducting polymer poly (3, 4-phenylenedioxythiophene) is synthesized by the electrochemical polymerization technique with different solvents. We find that solvents used in electrochemical polymerization play important roles for the catalytic activity and morphology of the formed conducting polymers. The obtained poly (3, 4-phenylenedioxythiophene) is for the first time employed as counter electrode electrocatalyst in dye sensitized solar cells with cobalt-based electrolytes. We demonstrate that a polymer prepared from a mixed acetonitrile-dichloromethane solvent exhibit higher catalytic activity for redox reactions, as compared to that from a single solvent, dichloromethane. The devices based on this mixed solvent-based polymer from a mixed solvents show a high power conversion efficiency of 5.97%. An additional advantageous feature of the electrochemically polymerized poly (3, 4-phenylenedioxythiophene) for solar cell applications is the high transparency in the visible and near-infrared region. We also investigate the beneficial effect of the poly (3, 4-phenylenedioxythiophene) layer thickness on device performance, and concluded that the series resistance and charge transfer resistance are greatly influenced by the thickness of polymer, as evidenced by electrochemical impedance spectroscopy measurements. The optimal thickness for poly (3, 4-phenylenedioxythiophene) is about 100 nm. Furthermore, the high catalytic activity and transparency of the new conducting polymer as counter electrode shows great promise for other optoelectronic applications. © 2019
Sheibani, E. ,
Amini, M. ,
Heydari, M. ,
Ahangar, H. ,
Keshavarzi, R. ,
Zhang, J. ,
Mirkhani, V. Solar Energy (0038092X) 194pp. 279-285
N-annulated perylene based materials show outstanding and tunable optical and physical properties, making them suitable to be charge transport materials for optoelectronic applications. However, this type of materials has so far not been well studied in solar cells. Here, we develop a new hole transport material (HTM), namely S5, based on perylene building block terms, for organic-inorganic hybrid perovskite solar cells (PSCs). We have systematically studied the influences of the film thickness of S5 on their photovoltaic performance, and a low concentration of S5 with a thinner HTM film is favorable for obtaining higher solar cell efficiency. S5 shows excellent energy alignment with perovskite as well as high-quality thin film formation, and the PSCs based on S5 as HTMs show remarkable power conversion efficiency (PCE) of 14.90% with a much higher short-circuit photocurrent than that for conventional HTM spiro-OMeTAD (PCE = 13.01%). We conclude that the superior photocurrent for S5 is mainly attributed to the enhanced interfacial hole transfer kinetics as well as the high hole conductivity. In addition, we have investigated the stability of N-annulated perylene derivative as HTMs in PSCs devices, showing that the unencapsulated devices based on S5 demonstrate outstanding stability by remaining 85% of initial PCEs in ambient condition with a relative humidity of ~30–45% for 500 h, while for devices with spiro-OMeTAD the cell efficiency degrade to 57% of initial performance at the same conditions. © 2019 International Solar Energy Society
Wang, L. ,
Sheibani, E. ,
Guo, Y. ,
Zhang, W. ,
Li, Y. ,
Liu, P. ,
Xu, B. ,
Kloo, L. ,
Sun, L. Solar RRL (2367198X) 3(9)
Carbazole is a promising core for the molecular design of hole-transport materials (HTMs) for solid-state mesoscopic solar cells (ssMSCs), such as solid-state dye-sensitized solar cells (ssDSSCs) and perovskite solar cells (PSCs) due to its low cost and excellent optoelectronic properties of its derivatives. Although carbazole-based HTMs are intensely investigated in ssMSCs and promising device performance is demonstrated, the fundamental understanding of the impact of linking topology on the properties of carbazole-based HTMs is lacking. Herein, the effect of the linking topology on the optical and electronic properties of a series of carbazole-based HTMs with 2,7-substitution and 3,6-substitution is systematically investigated. The results demonstrate that the 2,7-substituted carbazole-based HTMs display higher hole mobility and conductivity among this series of analogous molecules, thereby exhibiting better device performance. In addition, the conductivity of the HTMs is improved after light treatment, which explains the commonly observed light-soaking phenomenon of ssMSCs in general. All these carbazole-based HTMs are successfully applied in ssMSCs and one of the HTMs X50-based devices yield a promising efficiency of 6.8% and 19.2% in ssDSSCs and PSCs, respectively. This study provides guidance for the molecular design of effective carbazole-based HTMs for high-performance ssMSCs and related electronic devices. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Gatty, M.G. ,
Pullen s., ,
Sheibani, E. ,
Tian h., H. ,
Ott s., ,
Hammarström l., L. Chemical Science (20416520) 9(22)pp. 4983-4991
Co-sensitization of molecular dyes and catalysts on semiconductor surfaces is a promising strategy to build photoelectrodes for solar fuel production. In such a photoelectrode, understanding the charge transfer reactions between the molecular dye, catalyst and semiconductor material is key to guide further improvement of their photocatalytic performance. Herein, femtosecond mid-infrared transient absorption spectroscopy is used, for the first time, to probe charge transfer reactions leading to catalyst reduction on co-sensitized nickel oxide (NiO) photocathodes. The NiO films were co-sensitized with a molecular dye and a proton reducing catalyst from the family of [FeFe](bdt)(CO)6 (bdt = benzene-1,2-dithiolate) complexes. Two dyes were used: an organic push-pull dye denoted E2 with a triarylamine-oligothiophene-dicyanovinyl structure and a coumarin 343 dye. Upon photo-excitation of the dye, a clear spectroscopic signature of the reduced catalyst is observed a few picoseconds after excitation in all co-sensitized NiO films. However, kinetic analysis of the transient absorption signals of the dye and reduced catalyst reveal important mechanistic differences in the first reduction of the catalyst depending on the co-sensitized molecular dye (E2 or C343). While catalyst reduction is preceded by hole injection in NiO in C343-sensitized NiO films, the singly reduced catalyst is formed by direct electron transfer from the excited dye E2∗ to the catalyst in E2-sensitized NiO films. This change in mechanism also impacts the lifetime of the reduced catalyst, which is only ca. 50 ps in E2-sensitized NiO films but is >5 ns in C343-sensitized NiO films. Finally, the implication of this mechanistic study for the development of better co-sensitized photocathodes is discussed. © 2018 The Royal Society of Chemistry.
Sheibani, E. ,
Zhang, L. ,
Liu, P. ,
Xu, B. ,
Mijangos, E. ,
Boschloo, G. ,
Hagfeldt, A. ,
Hammarström l., L. ,
Kloo, L. ,
Tian h., H. RSC Advances (20462069) 6(22)pp. 18165-18177
Two new dyes, E1 and E2, equipped with triphenylamine as the electron donor, oligothiophene as the linker and different electron acceptor groups, have been designed and synthesized as photosensitizers for p-type dye-sensitized solar cells (p-DSCs). A systematic study of the effect of molecular structures on the observed photophysical properties, the electron/hole recombination process, the overall performance and the interfacial charge separation was carried out. Transient absorption spectroscopy (TAS) shows that the E1 dye with a napthoilene-1,2-benzimidazole (NBI) unit as the acceptor has a longer lifetime in the reduced state than the E2 dye with a malononitrile subunit on the NiO surface. © The Royal Society of Chemistry 2016.
Lindbäck, E. ,
Norouzi-arasi, H. ,
Sheibani, E. ,
Ma, D. ,
Dawaigher, S. ,
Wärnmark, K. ChemistrySelect (23656549) 1(8)pp. 1789-1794
The synthesis of two conformationally restricted Cr(III) salen complexes, 2 and 3, is described. Together, they constitute a supramolecular hydrogen-bonding catalytic system for the recently reported asymmetric ring-opening reactions of epoxides by a dynamic supramolecular catalyst. The synthesis involves state-of-the art transformations in frontline synthetic chemistry applied to heterocyclic chemistry. Hence, palladium-catalyzed reactions were employed, including carbonylative annelation and Suzuki cross-coupling reactions, for the formation of one of the heterocyclic rings (quinolone) and the functionalization of the formed rings. For the construction of the second heterocyclic ring (isoquinolone), a Curtius rearrangement was employed. The corresponding salen ligands were then prepared by Schiff-base reactions, yielding the final complexes after metal insertion. For reference purposes the less conformationally restricted Cr(III) complexes 4 and 5 were also synthesized. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Lindbäck, E. ,
Cherraben, S. ,
Francoïa, J. ,
Sheibani, E. ,
Lukowski, B. ,
Proç, A. ,
Norouzi-arasi, H. ,
Månsson, K. ,
Bujalowski, P. ,
Cederbalk, A. ChemCatChem (18673880) 7(2)pp. 333-348
A double conformationally restricted kinetically labile supra-molecular catalytic system, the third generation, was designed and synthesized. We investigated the substrate selectivity of this system by performing competitive pairwise epoxidations of pyridyl- and phenyl-appended olefins. We compared the obtained substrate selectivities to previous less preorganized generations of this system. Five different substrate pairs were investigated, and the present double conformationally restricted system showed higher normalized substrate selectivities (pyridyl versus phenyl) for two of the substrate pairs than the previous less conformationally restricted generations. As for the preorganization of the components of the system, the catalyst, and the receptor part, it was shown that for each substrate pair there was one generation that was better than the other to generate substrate-selective catalysis. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.
Organic and Biomolecular Chemistry (14770520) 10(10)pp. 2059-2067
A second generation of a substrate-selective dynamic supramolecular catalytic system consisting of a catalyst part and a receptor part, connected by a hydrogen-bonding motif, has been realized based on rational design. The results from analyses of the equilibrium mixture of the species generated by the components of the first generation system led us to selectively lock the cisoid conformation of the catalyst part to increase the amount of the substrate-selective catalytic cavity in the equilibrium mixture. This was realized by strapping the catalyst part by organic synthesis. This strapping led to an increase in substrate selectivity in the pair-wise competitive epoxidations of pyridyl- vs. phenyl-appended styrenes and pyridyl- vs. phenyl-appended stilbenes of both Z- and E- configuration compared to the first generation system, reaching 3.4:1 as the highest substrate selectivity for Z-mono-pyridyl-stilbene (27a) vs. the corresponding all-carbon analogue (28a) and for E-dipyridyl-stilbene (26b) vs. the corresponding all-carbon analogue (28b), respectively. © 2012 The Royal Society of Chemistry.
ChemCatChem (18673899) 2(6)pp. 629-632
Tetrahedron Letters (00404039) 50(31)pp. 4420-4422
A novel and efficient ring expansion of benzothiazoles to functionalized 1,4-benzothiazines is described. The reactive 1:1 zwitterionic intermediates formed by addition of benzothiazoles to diaroylacetylenes were trapped with Meldrum's acid under mild reaction conditions to produce 2-[2-hydroxy-2-aryl-2H-1,4-benzothiazin-3(4H)-yliden]-1-aryl-1-ethanones in excellent yields. © 2009 Elsevier Ltd. All rights reserved.
Tetrahedron (00404020) 64(47)pp. 10681-10686
An efficient, one-pot, multi-component synthesis of 3-amino-2-arylimidazo[1,2-a]pyridines, 3-amino-2-arylimidazo[1,2-a]pyrazines, and 3-amino-2-arylimidazo[1,2-a]pyrimidines is described. Heating a mixture of a 2-aminopyridine, 2-aminopyrazine or 2-aminopyrimidine, a benzaldehyde, and imidazoline-2,4,5-trione under solvent-free conditions afforded imine derivatives of the title compounds in excellent yields. Single-crystal X-ray analysis conclusively confirms the structure of these bridgehead bicyclic 5-6 heterocycles. © 2008.
Tetrahedron Letters (00404039) 49(34)pp. 5108-5110
An efficient synthesis of 3-amino-2-arylimidazo[1,2-a]pyridines is described via a novel multicomponent reaction between 2-aminopyridines, benzaldehydes and imidazoline-2,4,5-trione under solvent-free conditions. © 2008 Elsevier Ltd. All rights reserved.
Synlett (09365214) (19)pp. 2941-2944
An efficient synthesis of imidazo[2,1-b][1,3]benzothiazoles and 9H-imidazo[1,2-a][1,3]benzimidazoles is described from a novel multicomponent reaction between 2-aminobenzothiazoles or 2-aminobenzimidazole, benzaldehydes, and imidazoline-2,4,5-tri-one under solvent-free conditions. © Georg Thieme Verlag Stuttgart.
Tetrahedron Letters (00404039) 48(7)pp. 1179-1182
The reactive 1:1 zwitterionic intermediate formed by the addition of triphenylphosphine to diaroylacetylenes was trapped with 1,2-benzenediamines to produce triphenylphosphorane intermediates. Intramolecular cyclization and subsequent oxidation of the intermediate afforded functionalized α-quinoxalinyl triphenylphosphoranes in good to excellent yields. © 2006 Elsevier Ltd. All rights reserved.
Adib, M. ,
Sheibani, E. ,
Mostofi, M. ,
Ghanbary, K. ,
Bijanzadeh, H.R. Tetrahedron (14645416) 62(14)pp. 3435-3438
1-Alkyl imidazoles react smoothly with dialkyl acetylenedicarboxylates in the presence of pyridine carboxaldehydes to diastereoselectively produce 1,8a-dihydro-7H-imidazo[2,1-b][1,3]oxazine derivatives in excellent yields. © 2006 Elsevier Ltd. All rights reserved.
Monatshefte fur Chemie (00269247) 137(2)pp. 191-196
The reactive 1:1 intermediate produced in the reaction between isocyanides and dialkyl acetylenedicarboxylates was trapped by hydantoins to yield highly functionalized stable ketenimines in fairly good yields. © Springer-Verlag 2006.
Adib, M. ,
Sheibani, E. ,
Mostofi, M. ,
Ghanbary, K. ,
Bijanzadeh, H.R. Phosphorus, Sulfur and Silicon and the Related Elements (10426507) 180(12)pp. 2701-2707
Crystalline phosphorus ylides are obtained in nearly quantitative yields from the addition reaction between triphenylphosphine, dialkyl acetylenedicarboxylates, and imidazolidine-2-thione. A dynamic NMR effect is observed in the 1H NMR spectrum of the stabilized ylide obtained from dimethyl acetylenedicarboxylate (ΔG≠ = 66.6 kJmol -1) and is attributed to restricted rotation around the carbon-carbon partial double bond resulting from the conjugation of the ylide moiety with the adjacent carbonyl group. Copyright © Taylor & Francis Inc.
Hole Transport Materials (HTMs) play a pivotal role in a diverse array of cutting-edge optoelectronic devices prevalent in today's technological landscape. These materials are indispensable for the functionality and performance optimization of various technologies, including displays like Organic Light-Emitting Diodes (OLEDs) and photovoltaic devices like Perovskite Solar Cells (PSCs). The continuous advancement of OLEDs and PSCs over recent decades has spurred the innovation and development of a multitude of HTMs, each characterized by unique structural features. Presently, a notable trend is observed in the utilization of specific small organic molecules, such as carbazoles, as constituents of HTMs. Carbazole-based HTMs exhibit exceptional photovoltaic properties when compared to their counterparts and can be synthesized at a reduced cost, thus driving further exploration and refinement in this domain. Consequently, there is a concerted effort to gain comprehensive insights into the characteristics and capabilities of this category of HTMs, with a particular emphasis on Carbazole-Based Hole Transport Layers (HTLs). Therefore, Leveraging the intrinsic attributes of Carbazole-Based HTLs, researchers have focused on elucidating critical parameters such as Highest Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) energy levels, Glass Transition Temperatures (Tg), hole mobilities, among others. These data serve as invaluable assets for researchers engaged in interdisciplinary fields spanning chemistry, materials science, electrical engineering, and physics. This investigation stands as a succinct yet comprehensive resource, delving into the intricacies of Carbazole-Based HTLs within the contexts of OLEDs and PSCs. By offering valuable insights and understanding into the design and optimization of HTMs, this study serves as a guiding beacon for researchers, catalyzing further advancements in the field of optoelectronics. © 2024 Nova Science Publishers, Inc. All rights reserved.
Engineering Materials (16121317) pp. 119-135
Solar cells based on semiconductor heterojunction demonstrate tunable interfaces and high efficiency, showing great potentials in future applications. In heterojunction solar cells, charge transport materials play critical roles in carrier conductivity, recombination kinetics, and charge collection efficiency, which in turn significantly influence the photovoltaic parameters as well as the stability of solar cells. Traditional inorganic and molecular conductors exhibit high promises in optoelectronic properties, however, they are somewhat facing challenges in high material cost, poor device stability, and sophisticated fabricating processes. Alternatively, conducting polymers have been recently recognized as promising charge transport materials due to their advantages of high conductivity, tunable work function, controllable transmittance, and high stability. Careful design and optimization of polymer chemical structures have promoted fast development in tuning their optoelectronic properties and enhancing photovoltaic performance. Therefore, in this chapter, we summarize the recent progress of strategies in designing new conducting polymer materials as a charge transport medium for solar cell application. The current challenges and prospects in the future development of polymer-based charge conductors are discussed. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
A new field of two-dimensional (2D) physics has been opened by 2D atomic crystals represented by graphene in recent years. Despite a relatively short research history, the exceptional electrical and optical characteristics of 2D semiconductors make them highly attractive for electronic and optoelectronic purposes. The electronic and optical properties of 2D semiconducting materials (SCMs) are significantly influenced by the molecular orbital (MO) delocalization and stacking effects. These effects play a crucial role in determining the performance and efficiency of these materials in various applications, including electronics, optoelectronics, and energy devices. The phenomenon of MO delocalization in 2D SCMs refers to the spread of electronic wavefunctions over multiple atoms within the material. In these materials, the interaction between adjacent layers leads to the formation of new electronic states called interlayer coupling or interlayer hybridization. This delocalization affects the electronic band structure of the material, including the position of the conduction and valence bands, the bandgap, and the effective masses of charge carriers. Moreover, the consideration of stacking effects is of utmost importance for 2D SCMs. The stacking arrangement of layers can influence the electronic properties, such as the bandgap, optical properties, and the anisotropy of charge transport of 2D SCMs. These effects can alter the exciton dynamics, light-matter interactions, and emission characteristics of these materials. © 2025 Anuj Kumar and Ram K. Gupta.
In recent years, non-fullerene acceptor materials have garnered significant attention and utilization in organic solar cells (OSCs) devices, primarily owing to their favorable optical properties and the ease of tuning their electronic energy levels through synthetic methods. The utilization of non-fullerene acceptors represents a prominent focal point in the ongoing research and development of bulk-heterojunction OSCs. Notably, recent advancements in this area have led to remarkable enhancements in power conversion efficiency (PCE), with PCE levels surpassing the 20 \% threshold. Perylene diimide (PDI), a prominent example of a non-fullerene acceptor material, has emerged as a subject of extensive investigation due to its favorable attributes such as high electron affinity and excellent charge transport properties. Its widespread study stems from its capacity for efficient light transmission and electron capture. Through an in-depth examination, the article elucidates the impact of PDI-based acceptor materials on OSC device efficiency and outlines the evolving landscape of their application in renewable energy technologies. © 2024 IEEE.
Ghahfarokhi, F.A. ,
Moslempoor, M. ,
Ahangar, H. ,
Sheibani, E.
The escalating global energy consumption is predominantly attributed to the burgeoning population growth, resulting in increased demand for energy resources; hence, the imperative to shift towards sustainable energy sources is emphasized. In this context, solar energy appears particularly promising due to its abundant, clean, and renewable characteristics. One significant aspect of solar cells is hole transport materials (HTMs), where we are currently witnessing a revolution in hole transport materials based on self-Assembled monolayers (SAM-HTMs); this category of materials has significantly contributed to notable enhancements in power conversion efficiencies (PCEs) in inverted perovskite solar cells (PSCs). Despite the fabrication of the first SAM-based PSC occurring in late 2018, SAM-HTMs have emerged as a promising alternative such as PTAA, primarily due to various advantages such, as tunable bandgap, robust interface stability, and easy fabrication. This class of materials holds the potential to advance the energy sector and expedite the rapid industrialization of PSCs. © 2024 IEEE.
The field of optoelectronics has experienced remarkable growth and innovation in recent decades, leading to the development of numerous cutting-edge technologies that have transformed various industries. These technologies have had an indelible impact on our daily lives, and environmentally friendly energy solutions. In the meantime, fibers based on semiconductor polymers represent a remarkable class of materials at the promising frontier of polymer science with electronics and optoelectronics. These elongated structures, composed of organic polymers with conjugated molecular architectures, exhibit semiconducting behavior, which makes them pivotal in the realm of modern electronics and optoelectronics. Semiconducting polymer fibers offer a unique blend of characteristics, including mechanical flexibility, low cost, lightweight composition, and the ability to transport electrical charge, which distinguishes them from conventional inorganic semiconductors. Their versatility extends to applications spanning flexible electronics, light-emitting diodes (LEDs), photovoltaic devices, sensors and wearable technology. This innovative class of materials holds the promise of revolutionizing various industries by enabling the development of cutting-edge, lightweight and adaptable electronic and photonic technologies. As research continues to advance, fibers based on semiconductor polymers remain at the forefront of materials science, driving progress toward more flexible and sustainable electronic solutions. © 2025 selection and editorial matter, Ram K. Gupta; individual chapters, the contributors.
Moslempoor, M. ,
Ahangar, H. ,
Ghahfarokhi, F.A. ,
Sheibani, E.
Significant attention is directed towards advancing dyesensitized solar cells (DSSCs). DSSCs comprise a complex assembly of components, each playing a critical role in facilitating efficient energy conversion. Of particular significance are the hole transport materials (HTMs), which serve as integral components responsible for transporting positive charges within the cell. HTMs encompass various classes of materials, in the meantime small organic compounds have emerged as the forefront contenders for facilitating charge transport in Solid-state dye-synthesized solar cells (ssDSCs).Triphenylamine and carbazol emerge as a prominent candidate, owing to its unique chemical structure and inherent electrondonating properties. Triphenylamine exhibits a pronounced capacity for donating electrons, primarily attributed to the lone pair of nitrogen atoms and the arrangement of three phenyl rings within its molecular framework. This structural configuration facilitates efficient charge transfer mechanisms within the solar cell, consequently enhancing the stability and performance of solid-state dye-sensitized solar cells. © 2024 IEEE.
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