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Strain engineering in perovskite solar cells and its impacts on carrier dynamics

The mixed halide perovskites have emerged as outstanding light absorbers for efficient solar cells. Unfortunately, it reveals inhomogeneity in these polycrystalline films due to composition separation, which leads to local lattice mismatches and emergent residual strains consequently. Thus far, the...

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Detalles Bibliográficos
Autores principales: Zhu, Cheng, Niu, Xiuxiu, Fu, Yuhao, Li, Nengxu, Hu, Chen, Chen, Yihua, He, Xin, Na, Guangren, Liu, Pengfei, Zai, Huachao, Ge, Yang, Lu, Yue, Ke, Xiaoxing, Bai, Yang, Yang, Shihe, Chen, Pengwan, Li, Yujing, Sui, Manling, Zhang, Lijun, Zhou, Huanping, Chen, Qi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6379394/
https://www.ncbi.nlm.nih.gov/pubmed/30778061
http://dx.doi.org/10.1038/s41467-019-08507-4
Descripción
Sumario:The mixed halide perovskites have emerged as outstanding light absorbers for efficient solar cells. Unfortunately, it reveals inhomogeneity in these polycrystalline films due to composition separation, which leads to local lattice mismatches and emergent residual strains consequently. Thus far, the understanding of these residual strains and their effects on photovoltaic device performance is absent. Herein we study the evolution of residual strain over the films by depth-dependent grazing incident X-ray diffraction measurements. We identify the gradient distribution of in-plane strain component perpendicular to the substrate. Moreover, we reveal its impacts on the carrier dynamics over corresponding solar cells, which is stemmed from the strain induced energy bands bending of the perovskite absorber as indicated by first-principles calculations. Eventually, we modulate the status of residual strains in a controllable manner, which leads to enhanced PCEs up to 20.7% (certified) in devices via rational strain engineering.