一种低温退火处理提高锡基钙钛矿太阳能电池效率的方法

A Method for Improving the Efficiency of Tin-based Perovskite Solar Cells byLow Temperature Annealing Treatment

钙钛矿光伏材料是目前最具发展前景的一类光伏材料,其铅基光伏器件的小面积认证效率已突破25%。然而,铅元素严重的毒性问题成为钙钛矿光伏实用化的重要阻碍之一。锡基钙钛矿材料因其低毒性和理想的光电性能被认为是最有可能替代铅基钙钛矿的候选材料。然而,锡基钙钛矿过快的晶体生长速率往往造成制备的薄膜质量欠佳,限制了锡基钙钛矿太阳能电池(TPSC)光电转换效率的提高。本研究在锡基钙钛矿薄膜的制备流程中引入了一种低温退火处理,即在钙钛矿薄膜旋涂结束后先进行低温退火再进行常规的90℃退火。该处理可在不改变钙钛矿晶型且不引入新的组分的前提下减缓钙钛矿薄膜结晶过程中的晶体生长,从而减少锡基钙钛矿薄膜表面的孔洞缺陷,提高薄膜的光捕获能力,降低器件内载流子复合。最优器件效率由3.65%提高到了5.38%,填充因子提高了29.84%。

I in-based perovskite has been considered as a candidate material to replace lead based perovskite because of its ideal band gap and high carrier efficiency.However,the rapid crystallization rate has been one of the obstacles limiting the photoelectric conversion of tin-based perovskite solar cells.A simple and low-cost method is used here.After spinning perovskite film is annealed at low temperature,and then annealed at 90℃.The objective is to slow down the growth of perovskite crystals in the process of crystallization without changing the type of perovskite crystals and introducing new components.By this method,the light absorption efficiency of perovskite thin films is improved,the surface hole defects are reduced,and the carrier recombination in the device is reduced.Equipment filling coefficient increased by 29.84%,efficiency increased from 3.645%to 5.38%.