Achieving over 42 % indoor efficiency in wide-bandgap perovskite solar cells through optimized interfacial passivation and carrier transport

Leveraging their tunable bandgap and low-cost fabrication, mixed-halide perovskite solar cells (PSCs) are highly attractive for indoor light-harvesting applications. However, achieving efficient carrier transport and defect passivation at the critical nickel oxide (NiOx)/perovskite x )/perovskite interface, particularly under low light conditions, remains a challenge. Self-assembled monolayers (SAMs) offer a promising solution by introducing a tailored interface that promotes perovskite growth, suppresses non-radiative recombination, and facilitates efficient carrier transport. This study explores the effect of self-assembled monolayers (SAMs), readily deposited via spin- coating, on defect passivation in sol-gel NiOx x for PSCs. Four SAMs with varying linker lengths (2C- and 4C- aliphatic chains) and terminal functional groups (R=H, methoxy, benzo (C4H4-) methyl) were examined: 2PACz, MeO-2PACz, 4PADCB, and Me-4PACz. The results demonstrate that NiOx x films modified with MeO2PACz and 4PADCB are particularly effective in mitigating interface defects. Notably, PSCs incorporating these SAM-modified NiOx x layers and employing a wide-bandgap perovskite (Cs(0.18)FA(0.82)Pb(I0.8Br0.2)(3)) achieved impressive performance exceeding 20 % under simulated sunlight (AM 1.5 G 100 mW cm(-2) ) and a remarkable 42% PCE under indoor lighting condition (3000K LED (1000 lx)). This finding highlights the significant potential of PSCs for efficient electricity generation in low-light environments, potentially paving the way for their widespread application in such settings.