Retarding the Growth Kinetics of Chemical Bath Deposited Nickel Oxide Films for Efficient Inverted Perovskite Solar Cells and Minimodules.

Xu, Ping; Chen, Xin; Hui, Wei; Wang, Qi; Xu, Zhilu; Fan, Ben; Song, Lin; Xu, Xiaopeng et al. · Adv Mater · 2025

basic_science · Level V

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Abstract

The interfacial contact between the hole transport layer (HTL) and perovskite layer plays a critical role in determining the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Herein, to address the limitations of commercial NiO<sub>x</sub> nanoparticles and realize low temperature fabrication of compact NiO<sub>x</sub> film, a chemical bath deposition (CBD) approach is employed and strategically modified. By introducing an amino-alcohol ligand of triisopropanolamine (TPA) into the precursor, the deposition process is effectively controlled. TPA binds strongly with Ni<sup>2+</sup> ions, facilitating their gradual release and promoting the in situ formation of a compact Ni(OH)<sub>2</sub> intermediate. This retarded growth kinetics yield high-quality NiO<sub>x</sub> films with enhanced coverage, increased conductivity, and reduced trap-state. The films also feature abundant hydroxyl groups, providing sufficient anchoring sites for MeO-2PACz. Based on this bilayer HTL, a PCE of 26.53% (certified 26.44%) with improved operational stability is achieved for the 0.09 cm<sup>2</sup> device, marking the highest efficiency for inverted PSCs based on CBD NiO<sub>x</sub>. Furthermore, the strategy demonstrates excellent scalability, delivering efficiencies of 24.75% for a 1 cm<sup>2</sup> device and 22.96% for a 12.96 cm<sup>2</sup> minimodule. This work provides a facile but effective CBD approach for preparing high-quality NiO<sub>x</sub> films, offering a promising and scalable pathway for inverted PSCs.