Review
Chemistry, Multidisciplinary
Jun Yuan, Chujun Zhang, Beibei Qiu, Wei Liu, Shu Kong So, Mathieu Mainville, Mario Leclerc, Safa Shoaee, Dieter Neher, Yingping Zou
Summary: Organic solar cells (OSCs) have made rapid progress in recent years through the development of novel organic photoactive materials, particularly non-fullerene acceptors (NFAs). However, the understanding of the interplay between molecular structure and optoelectronic properties lags significantly behind. The potential role of energetic disorder in OSCs has received little attention, but recent studies have shown that state-of-the-art NFA-based devices can achieve both low energetic disorder and high power conversion efficiency (PCE).
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Shahidul Alam, Haya Aldosari, Christopher E. Petoukhoff, Tomas Vary, Wejdan Althobaiti, Maryam Alqurashi, Hua Tang, Jafar I. Khan, Vojtech Nadazdy, Peter Mueller-Buschbaum, Gregory C. Welch, Frederic Laquai
Summary: This study investigates the thermally-induced degradation of organic photovoltaic devices and its effect on their optical properties, photophysics, and morphology. The results show that the degradation limits the open-circuit voltage and fill factor of the devices, while the short-circuit current density is only slightly affected. Energy-resolved electrochemical impedance spectroscopy measurements reveal a higher energy barrier for charge transfer in the degraded samples. Furthermore, the study finds that field-dependent charge generation significantly limits device performance.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jiaying Wu, Hyojung Cha, Tian Du, Yifan Dong, Weidong Xu, Chieh-Ting Lin, James R. Durrant
Summary: The dynamics of charge carriers in organic solar cells and organic-inorganic hybrid metal halide perovskite solar cells were compared, discussing similarities and differences in charge generation, separation, transport, collection, and recombination, as well as their impact on device performance.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Jiaqi Xie, Weihua Lin, Guillermo C. Bazan, Tonu Pullerits, Kaibo Zheng, Ziqi Liang
Summary: N-type doping can improve electron transport in nonfullerene organic solar cells, leading to stronger photogeneration, longer exciton lifetime, and increased short-circuit current density and open-circuit voltage. The molecular n-dopant N-DMBI facilitates the crystallization of the blend and enhances optical absorbance. The dopant prolongs exciton lifetime by reducing germinate recombination, and despite slower interfacial charge transfer, exciton dissociation remains highly effective. This leads to improved photovoltaic performance, with higher short-circuit current density and open-circuit voltage achieved.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Chemistry, Physical
Zhizhao Cai, Xinyuan Ma, Jiefeng Cai, Zhenye Zhan, Dongxu Lin, Ke Chen, Pengyi Liu, Weiguang Xie
Summary: In this study, ultrathin BCP and ZrAcac were inserted between the perovskite and BHJ layers as an interface modification, successfully regulating carrier extraction and inhibiting charge recombination at the interface. This led to significant improvements in open-circuit voltage and fill factor, resulting in high conversion efficiency.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Multidisciplinary
Florian Hackl, Thomas Fromherz, Markus C. Scharber
Summary: We studied the charge transfer emission in a low band-gap blend used as an absorber for bulk-heterojunction solar cells. We found a short-lived emission but no evidence of long-lived radiative recombination. This explains the larger open circuit voltage loss in this solar cell compared to other types, highlighting a key process limiting its performance.
ISRAEL JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Zesheng Liu, Tengfei Li, Yuze Lin
Summary: Organic solar cells are a promising renewable energy technology due to their cost-effectiveness, adaptability, and lightweight nature. However, solar cells with thicker active layers have inferior performance compared to those with thin layers. Efforts have been made to understand the limitations of thick active-layer solar cells, develop high-performance materials, and optimize the cell structure.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Physical
Xue-jiao Zhou, Ting-ting Dai, Xiong Li, Yu-jiao Yan, Wen Xiong, Tao Lin, Jun Zhou, Deng-hui Xu, Yao-hui Zhu, Jia Zhao, Ai-cong Geng
Summary: Optimizing the active layer morphology is an effective strategy to improve the performance of organic solar cells. By using a binary solvent system of o-xylene and dichloromethane, the PM7:IT-4F OSCs showed improved crystallization and enhanced charge transport, leading to an increase in power conversion efficiency from 10.21% to 12.74%.
ACS APPLIED ENERGY MATERIALS
(2021)
Review
Energy & Fuels
Shaobing Xiong, Junhao Chu, Qinye Bao
Summary: This paper reviews the importance of the modulation of perovskite surface energetics for solar cells, including the effects of device structure evolution on surface energy-level alignment and modulation strategies such as defect doping, charge transfer, surface dipole formation, and surface reconstruction. These approaches contribute to enhanced charge carrier transport, leading to improved efficiency and stability of solar cells.
Article
Materials Science, Multidisciplinary
Sarah Alsaggaf, Raja Shahid Ashraf, Balaji Purushothaman, Neha Chaturvedi, Iain McCulloch, Frederic Laquai, Jafar Iqbal Khan
Summary: This study investigates the photophysics of a novel germanium-containing donor polymer blended with nonfullerene acceptors in bulk heterojunction solar cells. The results show that the efficiency is higher with O-IDTBCN as the acceptor compared to O-IDTBR, mainly due to the low photocurrent and moderate fill factor of the latter. Geminate recombination and field-dependent charge generation are identified as key factors affecting the performance of the solar cells.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Chemistry, Physical
Yanxun Li, Jianwei Ding, Cheng Liang, Xuning Zhang, Jianqi Zhang, Devon S. Jakob, Boxin Wang, Xing Li, Hong Zhang, Lina Li, Yingguo Yang, Guangjie Zhang, Xiaoxian Zhang, Wenna Du, Xinfeng Liu, Yuan Zhang, Yong Zhang, Xiaoji Xu, Xiaohui Qiu, Huiqiong Zhou
Summary: By introducing two-dimensional MoS2 nanosheets to tune the distribution of surface energy at the interlayers, this study successfully improved the performance of the BHJ layers in OSCs, including suppressing charge recombination, increasing charge extraction, and enhancing device stability.
Article
Chemistry, Physical
Yehui Xu, Shaobing Xiong, Sheng Jiang, Jianming Yang, Dong Li, Hongbo Wu, Xiaomeng You, Yefan Zhang, Zaifei Ma, Jianhua Xu, Jianxin Tang, Yefeng Yao, Zhenrong Sun, Qinye Bao
Summary: It is reported that using daminozide (DA) as an interlayer and additive can effectively suppress nonradiative recombination in perovskite solar cells, leading to improved power conversion efficiency and operational stability.
ADVANCED ENERGY MATERIALS
(2023)
Article
Energy & Fuels
Kazuki Kohzuki, Rei Shirouchi, Shin-ichiro Natsuda, Toshiharu Saito, Yuji Sakamoto, Yasunari Tamai
Summary: Suppressing charge recombination is crucial for enhancing the power conversion efficiency of organic solar cells (OSCs). The formation of both singlet and triplet charge transfer (CT) states in OSCs indicates that charge recombination via the triplet excited state is the main pathway for deactivation. However, it has been shown that charge separation from triplet excitons can occur in nonfullerene acceptor (NFA)-based OSCs, emphasizing the significance of minimizing the energy difference between singlet and triplet excited states of NFAs to suppress charge recombination.
Article
Chemistry, Physical
Kyra N. Schwarz, Valerie D. Mitchell, Saeed-Uz-Zaman Khan, Calvin Lee, Adam Reinhold, Trevor A. Smith, Kenneth P. Ghiggino, David J. Jones, Barry P. Rand, Gregory D. Scholes
Summary: The morphology of organic semiconductors plays a critical role in the function of optoelectronic devices, especially in donor-acceptor mixtures within organic solar cells. Energy landscapes are shown to drive charge accumulation away from interfaces, forming large electric fields, similar to a capacitor. Adjusting annealing conditions affects domain purity and electro-absorption, demonstrating the importance of energy landscapes in shaping charge movement and the necessity of pure domains for reduced recombination and large electric fields.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Humberto Emmanuel Sanchez-Godoy, K. M. Muhammed Salim, Ruben Rodriguez-Rojas, Isaac Zarazua, Sofia Masi
Summary: Zinc oxide suffers from chemical instability when in contact with perovskite interfaces, but this study has developed a new synthesis method using ethanolamine to passivate the zinc oxide nanoparticles in situ, effectively improving its stability. The research demonstrates the feasibility of using ethanolamine-passivated zinc oxide as an n-type charge extraction layer in methylammonium perovskite.
Article
Chemistry, Multidisciplinary
Changzeng Ding, Li Yin, Jinlong Wang, Valentina Larini, Lianping Zhang, Rong Huang, Mathias Nyman, Liyi Zhao, Chun Zhao, Weishi Li, Qun Luo, Yanbin Shen, Ronald Osterbacka, Giulia Grancini, Chang-Qi Ma
Summary: In this paper, it is demonstrated that the burn-in degradation in n-i-p type perovskite solar cells (PSCs) is directly related to the migration of Li+ ions from the SnO2 electron transporting layer. To prevent ion movement, a thin cross-linked [6,6]-phenyl-C61-butyric acid methyl ester layer is introduced, resulting in the elimination of burn-in degradation and an increase in device power conversion efficiency.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yong Ryun Kim, Oskar J. Sandberg, Stefan Zeiske, Gregory Burwell, Drew B. Riley, Paul Meredith, Ardalan Armin
Summary: Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is a commonly used hole transport layer (HTL) in organic solar cells (OSCs). However, the presence of PSS- ions can deteriorate device performance. This study shows that PSS- ions can lead to local p-doping in donor:non-fullerene acceptor blends, resulting in photocurrent loss. To address these issues, a two-component HTL consisting of a self-assembled monolayer of 2PACz and PEDOT:PSS is reported, which improves the OSC performance.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Seyed Mehrdad Hosseini, Sebastian Wilken, Bowen Sun, Fei Huang, Sang Young Jeong, Han Young Woo, Veaceslav Coropceanu, Safa Shoaee
Summary: Reducing non-radiative recombination is essential for achieving high fill factors in organic solar cells. This study investigates the effect of energetic disorder and finds clear correlations between disorder, recombination coefficient, and non-radiative voltage loss. It suggests that a narrower distribution of charge transfer energies leads to longer decay time and reduced non-radiative losses, improving both fill factor and open circuit voltage. This highlights the importance of low energetic disorder materials in the commercialization of organic photovoltaics.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Drew B. Riley, Oskar J. Sandberg, Nasim Zarrabi, Yong Ryun Kim, Paul Meredith, Ardalan Armin
Summary: This study reports a novel photoluminescence-based probe that accurately quantifies the donor-acceptor domain size in organic photovoltaic (OPV) blends. The research shows that in high-efficiency non-fullerene acceptor (NFA) systems, larger domains are formed. However, the expected reduction in bimolecular recombination attributed to the enhanced domain sizes is not significant enough. It is further demonstrated that the reduction in bimolecular recombination is correlated to enhanced exciton dynamics within the NFA domains.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Nasim Zarrabi, Oskar J. Sandberg, Paul Meredith, Ardalan Armin
Summary: Organic semiconductors have various applications in areas such as light emission, photovoltaics, and optoelectronics. The characteristics of these devices are determined by the disordered nature of the molecular solid rather than energy bands. However, there are subgap states within the energy gap that may affect the performance of organic semiconductor devices. This Perspective discusses methods to determine these subgap states and their impact on device performance.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Optics
Oskar J. Sandberg, Christina Kaiser, Stefan Zeiske, Nasim Zarrabi, Sam Gielen, Wouter Maes, Koen Vandewal, Paul Meredith, Ardalan Armin
Summary: Researchers demonstrate that the dark saturation current in organic photodiodes is fundamentally limited by mid-gap trap states, which leads to an upper limit for specific detectivity. Photodiodes are widely used in industry and consumer electronics. The use of organic semiconductors has gained considerable interest due to their versatile optoelectronic properties and potential for low-cost manufacturing.
Article
Chemistry, Physical
Li Yin, Changzeng Ding, Chenguang Liu, Chun Zhao, Wusong Zha, Ivona Z. Mitrovic, Eng Gee Lim, Yunfei Han, Xiaomei Gao, Lianping Zhang, Haibin Wang, Yuanxi Li, Sebastian Wilken, Ronald Osterbacka, Hongzhen Lin, Chang-Qi Ma, Cezhou Zhao
Summary: Currently, the use of tin oxide and Spiro-OMeTAD as electron transport and hole transport materials, respectively, in perovskite solar cells (PSCs) hinders the performance and stability of the devices due to charge recombination and ion migration. This study introduces a molecule bridging layer of 3,5-bis(fluorosulfonyl)benzoic acid (FBA) onto the SnO2 surface, which effectively improves the energy level alignment and immobilizes Li+ ions in the electron transport layer (ETL), resulting in enhanced power conversion efficiency (PCE) of 24.26% without hysteresis. Additionally, the PSCs with the FBA passivation layer exhibit excellent moisture and operational stability, retaining over 80% of the initial PCE after 1000 hours of aging.
ADVANCED ENERGY MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Xingxing Qin, Xuelai Yu, Zerui Li, Jin Fang, Lingpeng Yan, Na Wu, Mathias Nyman, Ronald Oesterbacka, Rong Huang, Zhiyun Li, Chang-Qi Ma, Barbara Panunzi
Summary: Improving the thermal stability of polymer solar cells (PSC) is crucial for their industrialization. This paper systematically investigates the effect of high-temperature thermal annealing on the device performance of state-of-the-art polymer:non-fullerene (PM6:Y6) solar cells with an inverted structure. The results reveal that the overall performance decay is mainly attributed to the decrease in open-circuit voltage and fill factor, while the short circuit current remains relatively stable. Pre-annealing on specific films results in different performance decays, indicating that the degradation at the interface is the main reason for the overall performance decay. Further analysis confirms the increased interfacial charge recombination after thermal annealing.
Article
Materials Science, Multidisciplinary
Axel Luukkonen, Amit Tewari, Kim Bjorkstrom, Amir Mohammad Ghafari, Eleonora Macchia, Fabrizio Torricelli, Luisa Torsi, Ronald Osterbacka
Summary: This study aims to investigate the long-term stability of a poly-3-hexylthiophene (P3HT) organic water-gated thin-film transistor (WG-TFT) operated intermittently over 5750 measurement cycles. Short-term performance changes are mainly attributed to work function changes on the gate electrode, while long-term performance changes are consistent with an increase in the semiconductor trap density. The shift in threshold voltage and decrease in mobility are linearly related to the measurement cycles and caused by electrical stress, while the time immersed in water has little effect on the device.
ORGANIC ELECTRONICS
(2023)
Article
Physics, Multidisciplinary
N. M. Wilson, H. Aarnio, R. Osterbacka
Summary: This work demonstrates how to obtain reliable data from frequency-dependent continuous-wave modulation spectroscopy. The example of continuous-wave photoinduced absorption (cwPA) is used to illustrate the technique's usefulness in studying long-lived photoexcitations in thin-film solar cell materials. The paper identifies and corrects experimental errors arising at moderate frequencies in modulation spectroscopy and addresses limitations caused by detectors and electronics. The outlined methods serve as a guide to avoid pitfalls and correct for limitations in modulation spectroscopy measurements.
Article
Materials Science, Multidisciplinary
Harald Reinhold, Ulf Mikolajczak, Holger Borchert, Juergen Parisi, Dorothea Scheunemann
Summary: Copper indium disulfide nanoparticles are being studied as an absorber material in light harvesting devices. However, the preparation of thin films from colloidal solution is challenging due to the presence of long organic ligand molecules. In this study, an alternative approach of thermal removal of ligands and sintering is explored to create conductive films without ligand exchange. The results of the nanoparticle film preparation, structural investigation, and conductivity measurements are presented.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Review
Nanoscience & Nanotechnology
Dorothea Scheunemann, Clemens Goehler, Constantin Tormann, Koen Vandewal, Martijn Kemerink
Summary: With power conversion efficiencies approaching 20%, organic solar cells have gained recognition in the field of photovoltaics. However, there is still a need for further improvement in energy and current management. The interpretation schemes for associated losses of energy and charge vary, hindering the design of next-generation organic solar cells. This article reviews important concepts, addresses open questions, and highlights implications for device performance and improvement.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Energy & Fuels
Austin M. Kay, Maura E. Fitzsimons, Gregory Burwell, Paul Meredith, Ardalan Armin, Oskar J. Sandberg
Summary: Organic semiconductors have tailorable optical properties, making them promising materials for indoor photovoltaics (IPVs) to power Internet-of-Things devices sustainably in the future. However, the excitonic and energetically disordered nature of organic semiconductors results in considerable sub-gap absorption and non-radiative losses in solar cells. This work explores how energetic disorder, sub-optical gap absorption, and non-radiative recombination limit the performance of organic semiconductor-based IPVs, providing realistic upper estimates for power conversion efficiency. Additionally, a methodology for predicting IPV performance under arbitrary illumination conditions is described.
Article
Materials Science, Multidisciplinary
Stefan Zeiske, Christina Kaiser, Oskar J. Sandberg, Tove Ericson, Paul Meredith, Charlotte Platzer-Bjorkman, Ardalan Armin
Summary: This study investigates the impact of cadmium sulfide buffer layers on the performance of kesterite (Cu2ZnSnS4) photodetectors. The results demonstrate that devices with a 100 nm cadmium sulfide layer exhibit the best performance, achieving a linear dynamic range of 180 dB and frequency responses in the range of tens of kHz. The key limiting factors are identified as shunt resistance-induced thermal noise and defect-induced nonradiative losses. Additionally, the upper radiative limit of specific detectivity is estimated to be approximately 1019 Jones. These findings highlight the potential of kesterites as interesting earth abundant candidates for photodetection applications.
ADVANCED PHOTONICS RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Davide Giavazzi, Marvin F. Schumacher, Luca Grisanti, Mattia Anzola, Francesco Di Maiolo, Jennifer Zablocki, Arne Luetzen, Manuela Schiek, Anna Painelli
Summary: This study provides a combined experimental and theoretical investigation of a new type of chiral aggregates with structure-correlated excitonic properties in the visible to near-infrared spectral range. It is found that different alkyl chain lengths can lead to different aggregation scenarios and spectroscopic features, including simultaneous blue- and red-shifted signatures, as well as dominant blue-shifted signatures. The calculation of circular dichroism including intermolecular charge transfer is explicitly expressed for the first time.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
