Li Yuhuan, Yang Tongxiao, She Yaqi, Xu Beizheng, Du Yonghui, Zhang Miao
Department of Physics, School of Sciences, Beihua University, Jilin 132013, China.
School of Materials Science and Engineering, Beihua University, Jilin 132013, China.
Inorg Chem. 2023 Nov 27;62(47):19248-19255. doi: 10.1021/acs.inorgchem.3c02516. Epub 2023 Nov 13.
Inorganic lead-free vacancy-ordered double perovskites with the chemical formula ABX are promising candidates to overcome Pb-based organic-inorganic perovskite's toxicity and instability issues. We designed the mixed-halide double perovskites CsPdBrI by halogen anions substitution. The structure, stability, and electronic and photoelectric properties were explored using density functional theory (DFT). The negative value of the formation energy indicated that the CsPdBrI perovskites are thermodynamically stable. These perovskites exhibit tunable bandgap values in the range of 0.77-1.73 eV, which are direct or quasi-direct bandgaps except for CsPdBrI. Their absorption spectrum shows that the absorption range of visible light expands significantly. The theoretical spectral limit maximum efficiency (SLME) of CsPdBrI with 1.3 eV and CsPdBrI with 1.04 eV reached 32 and 30.4%, respectively, which are becoming comparable to or slightly surpassing CHNHPbI, indicating they could be candidates for single-junction solar cells. In addition, the CsPdBrI and the CsPdBrI, with the bandgap of 1.12 and 1.04 eV, respectively, could be the bottom cell to form the homogeneous tandem solar cells with the CsPdBr, which could be the top cell with the bandgap of 1.73 eV.
化学式为ABX的无机无铅空位有序双钙钛矿是克服铅基有机无机钙钛矿毒性和稳定性问题的有前途的候选材料。我们通过卤素阴离子取代设计了混合卤化物双钙钛矿CsPdBrI。使用密度泛函理论（DFT）探索了其结构、稳定性以及电子和光电性质。形成能的负值表明CsPdBrI钙钛矿在热力学上是稳定的。这些钙钛矿的带隙值在0.77 - 1.73 eV范围内可调，除CsPdBrI外均为直接或准直接带隙。它们的吸收光谱表明可见光吸收范围显著扩大。带隙为1.3 eV的CsPdBrI和带隙为1.04 eV的CsPdBrI的理论光谱极限最大效率（SLME）分别达到32%和30.4%，这已与CHNHPbI相当或略超CHNHPbI，表明它们可能是单结太阳能电池的候选材料。此外，带隙分别为1.12 eV和1.04 eV的CsPdBrI和CsPdBrI可以作为底电池，与带隙为1.73 eV的CsPdBr（可作为顶电池）形成同质串联太阳能电池。
