Perovskite solar cells based on spin-coated (CH₃NH₃)₃Bi₂I₉ and Cs₃Bi₂I₉ thin films were fabricated, and the thickness-dependent structural, morphological, optical, and photovoltaic properties were studied. The x-ray diffraction studies revealed the formation of a hexagonal structure in the studied perovskite layers, and an improvement in crystallinity and morphology was also observed with increasing thickness. The absorption coefficient was of the order of 10⁴ cm⁻¹, and depending on film thickness, the band gap values varied from 1.70 eV to 2.02 eV and from 1.95 eV to 2.25 eV for (CH₃NH₃)₃Bi₂I₉ and Cs₃Bi₂I₉ active layers, respectively. We also investigated the effect of the thickness of these films on device performance. Results showed that with increasing thickness of the active layers, improvements of 21% in open-circuit voltage (V_OC) and 36% in efficiency were observed for (CH₃NH₃)₃Bi₂I₉ perovskite devices, compared with improvements of 28% and 57% in V_OC and cell efficiency, respectively, for Cs₃Bi₂I₉ solar cells.

制备了基于旋涂的（CH ₃ NH ₃）₃ Bi ₂ I ₉和Cs ₃ Bi ₂ I ₉薄膜的钙钛矿太阳能电池，并研究了厚度依赖性的结构，形态，光学和光伏特性。X射线衍射研究表明，在所研究的钙钛矿层中形成了六边形结构，并且随着厚度的增加，结晶度和形态也得到了改善。吸收系数约为10 ⁴  cm ^-1并且，根据膜厚，（CH ₃ NH ₃）₃ Bi ₂ I ₉和Cs ₃ Bi ₂ I ₉有源层的带隙值分别从1.70 eV至2.02 eV和从1.95 eV至2.25 eV变化。我们还研究了这些膜的厚度对器件性能的影响。结果表明，随着有源层厚度的增加，（CH ₃ NH ₃）₃ Bi ₂ I ₉的开路电压（V _OC）和效率提高了36％。钙钛矿器件，具有28％的改进和在57％相比，V _OC分别和电池效率，针对CS ₃的Bi ₂我₉太阳能电池。