Lead-free double perovskite Cs₂AgBiBr₆ has attracted much attention due to its environmental stability and low toxicity, which has bee used in photovoltaic devices. Unfortunately, the power conversion efficiency (PCE) is relatively low owing to poor-quality film. In this paper, CuBr₂ was added in the precursor to improve the crystalline of the perovskite film. Maybe Cu²⁺ was reduced to Cu ⁺ by DMSO, so Cu ⁺ existed in the Cs₂(Ag_1-xCu_x)BiBr₆ perovskite films. The carbon electrode-based and hole-free solar cells with the planar structure of FTO/c-TiO₂/Cs₂(Ag_1-xCu_x)BiBr₆/C were fabricated. The effect of CuBr₂ content on the performance of solar cells were studied. When the content of CuBr was 1 at.%, the solar cell exhibited the optimal PCE of 1.30%, which was increased by 52%, compared with the original solar cell. And the PCE for the planar structure in this work was the highest, compared with that in the other reported works.

无铅双钙钛矿Cs ₂ AgBiBr ₆因其环境稳定性和低毒性而备受关注，已被应用于光伏器件中。不幸的是，由于薄膜质量差，功率转换效率 (PCE) 相对较低。本文通过在前驱体中加入CuBr _{2来改善钙钛矿薄膜的结晶性。}可能Cu ²⁺被DMSO还原成Cu  ⁺  ，所以Cu  ⁺ 存在于Cs ₂ (Ag _1-x Cu _x )BiBr ₆钙钛矿薄膜中。_{FTO/c-TiO 2} /Cs平面结构碳电极基无孔太阳能电池制作了₂ (Ag _1-x Cu _x )BiBr _{6 /C。研究了CuBr 2}含量对太阳能电池性能的影响。当CuBr的含量为1at.%时，太阳能电池的最佳PCE为1.30%，与原始太阳能电池相比提高了52%。与其他报道的作品相比，这项工作中平面结构的 PCE 最高。