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

The carbazole-fused propeller-shaped non-planar hexaarylbenzene (HAB)-based compound K5-36, used as a hole selective layer in combination with the SAM of 4PADCB and hybrid perovskite in a p-i-n PSC device, induced the growth of larger perovskite grains and effectively suppressed non-radiative recombination. Notably, the best PCE reached 42.02% under dim-light conditions, demonstrating competitive potential comparable to high-efficiency PSCs.

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/PC₆₁BM/BCP/Ag, the interaction is investigated between the synthesized materials and self-assembled monolayer (4PADCB) elucidating mechanisms influencing the growth of wide bandgap Cs_0.18FA_0.82Pb(I_0.8Br_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.