Br-containing alkyl ammonium salt-enabled scalable fabrication of high-quality perovskite films for efficient and stable perovskite modules†
The development of new processing techniques with high reliability in large-scale fabrication is considered to be the most critical issue concerning organic–inorganic halide perovskite photovoltaics for their potential commercialization in the next few years. Herein, the incorporation of a Br-containing tetrabutylammonium salt (TBAB) into the perovskite precursors demonstrated superior advantages in both crystallization and large-area uniformity control during the scalable blade-coating of perovskite films. By this facile approach, the significantly increased repeatability in device performance and efficient large-area 16 cm2-four-cell modules with best-efficiency of up to 15.79% were achieved. More importantly, the surficial modification with the alkylammonium cations enabled the long-term stability of the MAPbI3-based perovskite films and modules, resulting in the fabricated modules retaining >89% of the initial PCE after 1000 h of aging. This study presents a facile method for achieving the synergistic effects of crystallization tailoring, uniformity control and surface passivation based on the Br-containing molecular modification strategy for perovskite films, leading to the significantly improved efficiency, stability and fabrication reliability of PSC modules.