Effect of Urea Addition on the Photovoltaic Performance of Perovskite Solar Cells

Abstract

钙钛矿太阳能电池以其成本低廉和优异的光电性能受到广泛的关注，其中钙钛矿光活性层的质量对组装电池的光电性能起着至关重要的作用。本文通过在钙钛矿前驱体溶液中添加路易斯碱——尿素(urea)，详细研究了尿素添加量对钙钛矿薄膜微结构和组装电池光电性能的影响。研究发现，钙钛矿前驱液中添加尿素是一种有效的获得大晶粒、致密平整钙钛矿薄膜的策略。高质量的钙钛矿薄膜减少了晶界，抑制了电池中载流子的复合，因而提升了器件的能量转换效率。在尿素添加量为10%时，组装电池具有18.90%的最佳能源转换效率。 Perovskite solar cells have attracted much attention due to their low cost and excellent photoe-lectric performance. The quality of the perovskite active layer plays a vital role in the performance of the solar cells. In this paper, urea as one of the Lewis bases has been added into the precursor solution of perovskite, and the effects of urea addition on the microstructure of perovskite thin films and the photovoltaic properties of the cells have been studied. It is found that the addition of urea in perovskite precursor is a promising strategy for obtaining compact and flat perovskite film with large grain size. The high quality of perovskite thin film reduces the grain boundaries of film, and suppresses the recombination of carriers. It therefore improves the photovoltaic performance of assembled perovskite solar cells. An optimum energy conversion efficiency of 18.90% was achieved in the cell with urea addition of 10% in the perovskite precursor.