Emerging Photovoltaic Materials and Devices
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2019-11-01 |
| Journal | Advanced Functional Materials |
| Authors | Kui Zhao, Yang Zhou, Shengzhong Liu |
| Citations | 10 |
Abstract
Section titled āAbstractāPhotovoltaic (PV) devices can directly convert solar energy into electricity, offering a practical, clean, and sustainable solution to address the challenge of the ever-increasing global energy demand. Current research is focused on identifying high efficiency solar cells with low-cost fabrication. Currently, PV devices based on various inorganic materials including silicon (Si), III-V group semiconductors, CdTe, and CIGS dominate the market. However, partially due to the high production cost and related environmental issues, conventional PV technology places obvious constraints on the scaling-up of and expenses related to the manufacturing capacity as well as their wide application. In recent years, there has been growing interest in emerging organic and perovskite-based PV technologies owing to their synthetic variability, low-temperature processing, and the possibility of producing lightweight, flexible, easily manufactured, and inexpensive solar cells using earth-abundant materials. It is our great pleasure to propose this special issue titled āEmerging Photovoltaic Materials and Devicesā for Advanced Functional Materials. The issue highlights important aspects in the research of emerging PV materials from both the fundamental research and the commercialization perspectives. We present a collection of 6 reviews and 12 feature articles from this exciting field that covers material science and device engineering for both organic and perovskite solar cells. A fundamental understanding of crystallization mechanisms during film fabrication and its influence on the morphological and optoelectronic properties of the active layer are important to improve the performance of solar cells. The complex crystallization mechanism from perovskite precursors to perovskite is well demonstrated by Anthopoulos, Zhao, Amassian, and co-workers using in situ grazing incidence wide-angle X-ray scattering (GIWAXS) measurements (article number 1807544). Direct and complete phase conversion from precursors to lead-based perovskite without the need for thermal annealing is realized for the first time, which could encourage novel and easy fabrication of perovskite solar cells in the future. Chen, Huang, and co-workers and Zhang, Zhu, and co-workers demonstrate the control of crystallization kinetics during solution processing of 2-dimensional (2D) perovskites by tuning the solvent properties or intermediate phase formation (article numbers 1806831 and 1901652). Liu, Han, and co-workers realize sequential crystallization of donors and acceptors during solution-processing organic bulk heterojunction (BHJ) organic thin films, which is critical to the formation of an interpenetrating network and the optimization of vertical phase separation (article number 1807591). Wadsworth and co-workers design a novel organic acceptor of O-IDTBCN with dicyano moieties end group, which allows complementary absorption to the donor and thus improved photon harvesting (article number 1808429). Yuan and coworkers report an easy strategy to control the crystal orientation of tin-based quasi-2D perovskite via dimensional tunability (article number 1807696). Zhu, Jen, and co-workers report composition engineering by employing BF4-anion substitutions for lattice relaxation and a longer photoluminescence lifetime in perovskite bulk crystals, leading to suppression of trap formation (article number 1808833). Huang and co-workers propose a bottom-up technique for the first time to grow wafer-like perovskite crystals from an aqueous solution (article number 1807707). Material stability is key to the commercialization of solar cells. Liu, Liu, and co-workers and Pan, Dai, and coworkers propose stabilization strategies for 3D perovskite materials by introducing a novel stabilizer or 2D perovskite components into the 3D bulk film (article numbers 1807850 and 1807565). Duan, Yang, and co-workers review current efforts to enhance stability and summarize the causes and mechanisms of degradation, taking into account all the cell components (photoactive layer, hole- and electron-transporting layers, electrode materials, and device encapsulation) (article number 1808843). Advances in charge extraction materials have played an important role in achieving efficient solar cells. Qiao, Zhu, and co-workers propose urea treatment of the hole transport material, PEDOT:PSS, to improve the conductivity of the material and the resulting perovskite solar cell performance (article number 1806740). Xu et al. successfully fabricate uniform and highly crystalline tin oxide (SnO2) electron transport layers at a low temperature (100 Ā°C) through combining spin-coating SnO2 nanocrystal solution with hydrothermal treatment, leading to high-performance flexible perovskite solar cells (1807604). Zinc oxide (ZnO) has been commonly used as an electron transport layer for organic solar cells, while it has, to a large extent, been neglected due to a chemical instability in contact with methylammonium-based perovskite (MAPbI3). Snaith and co-workers elucidate the degradation mechanism at ZnO-MAPbI3 interfaces by substituting MA with formamidinium and cesium (article number 1900466). Particularly, Seok and co-workers give a very comprehensive summary on the preparation, advantages, and challenges of metal oxide transport layers, which are predicted to be the most suitable charge transport layer for large-scale perovskite solar cell applications (article number 1900455). Upscaling high-performance devices holds promise for industrial implementation of solar cells. Qi and co-workers demonstrate scalable fabrication of stable, high-efficiency perovskite solar cells and modules (aperture of 22.8 cm2, PCE = 12%) utilizing room temperature sputtered SnO2 electron transport layers (article number 1806779). Zheng, Zhang, and co-workers further summarize the underlying determinants for upscaling high-quality perovskite solar cells when taking into account hydrodynamic characteristics and the crystallization thermodynamic mechanism of perovskite ink (article number 1807661). Lee, Park, and co-workers also reviewe strategies for large-scale fabrication and propose a deeper understanding of crystallization of perovskite films for large-area perovskite film formation (article number 1807047). In terms of tandem solar cells, which allows for the possibility of surpassing the Shockley-Queisser radiative limit for single-junction solar cells, Zhao, Yan, and co-workers summarize the main efforts towards the development of low-bandgap, mixed tin-lead perovskites and their applications in all-perovskite tandem solar cells (article number 1808801). This may facilitate the development of new approaches to achieve high efficiency all-perovskite tandem solar cells. The present special issue thus represents the state-of-the-art in this challenging and fascinating scientific area. We are also greatly indebted to all authors for their significant contributions and enthusiastic support. We also thank Wiley for their great editorial support. We sincerely hope that this special issue can help better understand the fundamental research and commercialization of novel photovoltaics, and that the readers of Advanced Functional Materials will find this special issue helpful and enjoy it! Kui Zhao received his bachelor and Ph.D. degree from Jilin University and the Chinese Academy of Science (CAS) in 2004 and 2009, respectively. Currently, he is a professor at Shaanxi Normal University. His current research interests focus on energy materials, including organic and perovskite-based photovoltaics and electronics. Zhou Yang received his bachelor degree in physics from Hebei Normal University in 2007, and Ph.D. in condensed matter physics from the University of Science and Technology of China in 2012 supervised by Prof. Xiaoliang Xu. During 2012-2014, He joined Prof. Can Liās group as a postdoc at Dalian Institute of Chemical Physics, CAS in 2012. Currently, he is an Associate Professor at Shaanxi Normal University. His research mainly focuses on third-generation solar cells, including quantum dot-sensitized solar cells and perovskite solar cells. Shengzhong (Frank) Liu received his Ph.D. degree from Northwestern University (Evanston, Illinois, USA) in 1992. After finishing his postdoctoral research at Argonne National Laboratory (Argonne, Illinois, USA), he joined high-tech companies in the US for research including nanoscale materials, thin film solar cells, laser processing and diamond thin films. In 2011, he was selected into Chinaās top talent recruitment program and now he is a professor at Shaanxi Normal University and Dalian Institute of Chemical Physics, Chinese Academy of Sciences.