| 초록 |
Organic-inorganic hybrid perovskite solar cells (PSCs) represent an exceptional candidate for next generation photovoltaic technology. However, the surface and boundary defect problems in the perovskite film are obstacles due to the non-radiative recombination and degradation centers, and thus restrict further improvements of the power conversion efficiencies (PCEs) and long-term stabilities of the PSCs. To address these problem, herein, we report a bis-imidazole based organic small molecule-based hole transport materials (HTMs) that can suppress interfacial defects of the perovskite with its functional groups working as Lewis bases. The surface passivation effect of perovskite film leads to the reduction in undesirable non-radiative recombination trap density as well as improves its crystallinity, consequently affects to the PCEs of PSCs from 16.3% to 18.3% together with the superior stability which maintain ~92% of its initial PCEs for ＞500 hours in an open atmosphere. |
