My research project

My publications


Li Bowei, Ferguson Victoria, Silva Ravi, Zhang Wei (2018) Defect Engineering towards Highly Efficient and Stable Perovskite Solar Cells,Advanced Materials Interfaces 5 (22) 1800326 Wiley
Metal halide perovskite solar cells are emerging candidates amongst the next-generation thin-film photovoltaic devices with extremely low fabrication cost and high power conversion efficiency. Defects (both in the bulk material and at the interfaces) are recognized as one of the most fundamental reasons for the compromised device performance and long-term stability of perovskite solar cells. In this review article, we analyse the possible origins of the defects formation in metal halide perovskites, followed by the rationalization of various approaches being utilized to reduce the density of defects. We demonstrate that defect engineering, including adding dopants in the precursor solutions, interface passivation, or other physical treatments (thermal or light stress) is an essential way to further boost the device performance and enhance their long-term stability. We note that although the exact mechanisms of defect elimination in some approaches are yet to be elucidated, the research on defect engineering is expected to have enormous impact on next wave of device performance optimisation of metal halide perovskite solar cells towards Shockley-Queisser limit.
Li Bowei, Xiang Yuren, Imalka Jayawardena K.D.G., Luo Deying, Wang Zhuo, Yang Xiaoyu, Watts John F., Hinder Steven, Sajjad Muhammad T., Webb Thomas, Luo Haitian, Marko Igor, Li Hui, Thomson Stuart A.J., Zhu Rui, Shao Guosheng, Sweeney Stephen J., Silva S. Ravi P., Zhang Wei (2020) Reduced bilateral recombination by functional molecular interface engineering for efficient inverted perovskite solar cells,Nano Energy 105249 Elsevier
Interface-mediated recombination losses between perovskite and charge transport layers are one of the main reasons that limit the device performance, in particular for the open-circuit voltage (VOC) of perovskite solar cells (PSCs). Here, functional molecular interface engineering (FMIE) is employed to retard the interfacial recombination losses. The FMIE is a facile solution-processed means that introducing functional molecules, the fluorene-based conjugated polyelectrolyte (CPE) and organic halide salt (OHS) on both contacts of the perovskite absorber layer. Through the FMIE, the champion PSCs with an inverted planar heterojunction structure show a remarkable high VOC of 1.18 V whilst maintaining a fill factor (FF) of 0.83, both of which result in improved power conversion efficiencies (PCEs) of 21.33% (with stabilized PCEs of 21.01%). In addition to achieving one of the highest PCEs in the inverted PSCs, the results also highlight the synergistic effect of these two molecules in improving device performance. Therefore, the study provides a straightforward avenue to fabricate highly efficient inverted PSCs.