Influence of post-annealing treatment on the performance of perovskite solar cells with different hole transport layers

The performance of perovskite solar cells (PSCs) is one of the key factors influencing their industrialization and market competitiveness. In this paper, post-annealing treatment, which is an effective and simple method, was used to enhance the performance of PSCs. PSCs with different hole transport layer (HTL) were prepared, and the effect of post-annealing treatment on the performance of PSCs was investigated. The results showed that post-annealing treatment could enhance the carrier extraction ability of HTL, reduce the defects in the perovskite layer, decrease non-radiative recombination, and effectively improve the device performance when PTAA was included in the HTL. After annealing treatment, it was found that the PCSs with NiOx/PTAA as the transport layer, the champion device of PSCs can achieve a PCE of 21.21 %. Compared to devices using only NiOx and PPAA as hole transport layers, the PCE increased by 36.9 % and 3 %, respectively. Meanwhile, when using NiOx/PTAA as the transport layer, compared to devices without annealing treatment, the PCE increased from 17.95 % to 21.21 %, resulting in an 18.2 % enhancement. The obtained results in this work can provide an important theoretical basis for researchers to understand the physical mechanism of post-annealing treatment on device performance and fabricate perovskite solar cells with high-performance.