Interface Engineering of Perovskite Hybrid Solar Cells with Solution-Processed Perylene–Diimide Heterojunctions toward High Performance

TLDR

Perovskite hybrid solar cells are promising for high power conversion efficiency and low‑cost fabrication, but further gains depend on minimizing interface losses through engineering. The study aims to integrate a solution‑processed perylene‑diimide (PDINO) cathode interlayer into pero‑HSCs to enhance performance. PDINO forms a highly qualitative contact with the top Ag electrode, reducing series resistance and increasing shunt resistance. Incorporating PDINO raised the PCE to 14.0 %, with values above 13 % across 5–24 nm thicknesses, surpassing both the 10.0 % reference PCBM/Ag device and the 11.3 % PCBM/ZnO/Ag device.

Abstract

Perovskite hybrid solar cells (pero-HSCs) were demonstrated to be among the most promising candidates within the emerging photovoltaic materials with respect to their power conversion efficiency (PCE) and inexpensive fabrication. Further PCE enhancement mainly relies on minimizing the interface losses via interface engineering and the quality of the perovskite film. Here, we demonstrate that the PCEs of pero-HSCs are significantly increased to 14.0% by incorporation of a solution-processed perylene–diimide (PDINO) as cathode interface layer between the [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) layer and the top Ag electrode. Notably, for PDINO-based devices, prominent PCEs over 13% are achieved within a wide range of the PDINO thicknesses (5–24 nm). Without the PDINO layer, the best PCE of the reference PCBM/Ag device was only 10.0%. The PCBM/PDINO/Ag devices also outperformed the PCBM/ZnO/Ag devices (11.3%) with the well-established zinc oxide (ZnO) cathode interface layer. This enhanced performance is due to the formation of a highly qualitative contact between PDINO and the top Ag electrode, leading to reduced series resistance (Rs) and enhanced shunt resistance (Rsh) values. This study opens the door for the integration of a new class of easily-accessible, solution-processed high-performance interfacial materials for pero-HSCs.