The Al2O3 passivation layer is beneficial for mesoporous TiO2-based perovskite solar cells when it is deposited selectively on the compact TiO2 surface. Such a passivation layer suppressing surface recombination can be formed by thermal decomposition of the perovskite layer during post-annealing.
Shaik Mohammed Zakeeruddin, Zhongjin Shen, Yelin Hu, Hongwei Zhu, Yinghui Wu, Jialin Wang, Miao Chen