On February 26th, the journal ofAdvanced Functional Materialspublished the research results of Bismuth Doping Induced Stable Seebeck Effect Based on MAPbI3Polycrystalline Thin Films by professor Hu Bin and assistant professor Xu Ling of Wuhan National Laboratory for Photoelectric. Doctor Xiong Yan is the first author of the paper, Hu Bin and Xu Ling is the co-corresponding author of the paper, and Huazhong University of Science and Technology is the only corresponding institution.
Organic-inorganic hybrid perovskite materials of CH3NH3PbI3(or MAPbI3), Miyasaka etc the first time used it as a solar cell material from 2009, which its photoelectric conversion efficiency was 3.8%, since it is great potential for development in the field of photovoltaic (pv), the photoelectric conversion efficiency is rapidly growing, today its photoelectric conversion efficiency is as high as 23.3%, which is expected to become the next generation of the representative of the new type of solar cells, but it also encountered the bottleneck of development: the temperature of water Oxygen and other environmental conditions will have an impact on its stability and life, which will hinder its commercial application.
Hu Bin and Xu Ling thoroughly studied the bismuth doped MAPbI3the thermoelectric properties of polycrystalline thin films, they found Bi doping can greatly improve the stability and thermal performance of MAPbI3, Bi dopant located the near grain boundary to modified boundary carrier channel, effectively reducing the ion migration and promote charge transport, in addition, Bi doping can passivation perovskite defects, increase MAPbI3polarization effect, which greatly improved the MAPbI3carrier’s mobility. Bi doping can also be induced by small grain MAPbI3perovskite, small grain size of the perovskite can not only prevent the occurrence of phase transition, it can also effectively improve the stability of perovskite structure. Bi doped perovskite make the seebeck voltage to change less than not doped perovskite, which also means that the Bi doping MAPbI3film more stable. These researches showed that the Bi doping organic-inorganic perovskite materials is an effective strategy to achieve stability of thermal and photovoltaic performance.
Figure 1. Thermoelectric properties of MAPbI3 with different Bi doping amount change with temperature, (a) Seebeck coefficient change with temperature, (b) I-V (current-voltage) curve characteristics change with temperature, (c) conductivity change with temperature, (d) power factor (PF) change with temperature.
This work was supported by Fund for Independent Iinnovation of Huazhong University of Science and Technology, and the Double first-class research funding with the independent intellectual property of ICARE.
Link: https://onlinelibrary.wiley.com/doi/10.1002/adfm.201900615
