Chemical bath deposition of planar nickel oxide films for inverted perovskite solar cells and mini‐modules

Abstract

Chemical bath deposition (CBD) is an economical method for the large‐scale preparation of high‐quality inorganic transport layer films. In the field of the n‐i‐p perovskite solar cells (PSCs), the devices based on n‐type CBD‐SnO2/CBD‐TiO2 structures have demonstrated significant advantages in efficiency and stability. However, using CBD method to deposit high‐quality planar p‐type NiOx is challenging due to the anisotropic growth of Nickle‐based intermediate phase. Herein, NH4Cl additive was introduced to modulate the intermediate phase by adjusting the concentration of [Ni(H2O)x(NH3)6‐x]2+ cations during the CBD process. As a result, dense and uniform NiOx films were finally obtained after simple thermal annealing. Simultaneously, the energy level and hole conductivity of NiOx materials were carefully controlled by adjusting the annealing temperature. Benefited from the excellent electronic properties of CBD‐NiOx hole transport layer, the inverted PSCs based on MAPbI3, (FA0.98MA0.02)0.95Cs0.05Pb(I0.95Br0.05)3 achieved the power conversion efficiency of 19.75% and 23.30%, respectively. Furthermore, the unencapsulated devices maintained over 90% of their initial efficiency after continuous operation for 700 hours. Scaling up this novel intermediate phase regulation CBD method yields a mini‐module with an active area of 14 cm2, achieving an efficiency of up to 19.36%. This not only established the groundwork for large‐area high‐efficiency devices but also promoted progress in the field of CBD methods.This article is protected by copyright. All rights reserved.