Researchers from Ming Chi University of Technology, National Taiwan University of Science and Technology and Chang Gung University have explored the effect of self-assembled monolayers (SAMs), readily deposited via spin-coating, on defect passivation in sol–gel NiOx for perovskite solar cells (PSCs).
The team explained that while mixed-halide PSCs are highly attractive for indoor light-harvesting applications (thanks to their tunable bandgap and low-cost fabrication), achieving efficient carrier transport and defect passivation at the critical nickel oxide (NiOx)/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.
Four SAMs with varying linker lengths (2C- and 4C- aliphatic chains) and terminal functional groups (Rdouble bondH, methoxy, benzo (C4H4-), methyl) were examined: 2PACz, MeO-2PACz, 4PADCB, and Me-4PACz. The results demonstrated that NiOx films modified with MeO-2PACz and 4PADCB are particularly effective in mitigating interface defects.
Notably, PSCs incorporating these SAM-modified NiOx layers and employing a wide-bandgap perovskite (Cs0.18FA0.82Pb(I0.8Br0.2)3) achieved impressive performance exceeding 20 % under simulated sunlight (AM 1.5 G 100 mW cm−2) and a 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.
