Enhanced Indoor Perovskite Solar Cells: Mitigating Interface Defects and Charge Transport Losses with Polyarene‐Based Hole‐Selective Layers

Abstract The study designs and synthesizes non‐planar, propeller‐shaped hexaarylbenzene‐type (HAB) compound K5‐36 and hexa‐ peri ‐hexabenzocoronene (HBC)‐based K5‐13 (with a cyclized core), as cost‐effective and high‐yielding hole selective layers (HSLs) for perovskite solar cells (PSC). Using a p–i–n device structure with ITO/4PADCB/HAB or HBC (with or without)/perovskite/PDADI/PC 61 BM/BCP/Ag, the interaction is investigated between the synthesized materials and self‐assembled monolayer (4PADCB) elucidating mechanisms influencing the growth of wide bandgap Cs 0.18 FA 0.82 Pb(I 0.8 Br 0.2 ) 3 perovskite. K5‐36 facilitates the growth of wide perovskite films with larger grains and lower defect density, while promoting energy level alignment at the HSL/perovskite interface. These modifications effectively suppressed non‐radiative recombination, resulting in a higher open‐circuit voltage of 1.2V and a power conversion efficiency (PCE) exceeding 20% under AM 1.5G conditions. Under 3000K LED (1000 lux) illumination, the PCE of 4PADCB/ K5‐36 ‐based PSCs significantly increased from 38.02 ± 0.38% (4PADCB PSC) to 41.80 ± 0.57%. Moreover, PSCs incorporating 4PADCB/ K5‐36 ‐ and 4PADCB/ K5‐13 ‐ demonstrate exceptional stability, retaining ≈88.5% and 98.2% of their initial PCE after 70 days of storage in a glove box. These findings highlight the potential of polyarene‐based HSLs as a promising approach for improving PSC efficiency and stability.