Dimerized Non-Fullerene Acceptor-based organic photovoltaics for Round-the-Clock functioning

Abstract

Organic photovoltaics (OPVs) have emerged as a key sustainable energy technology capable of efficiently generating electricity from both direct sunlight and low-intensity indoor lighting. Despite ongoing research to improve their performance, limited efforts have been undertaken to develop OPVs that can operate consistently (24/7/365) under versatile lighting conditions. For effective utilization, OPVs must demonstrate efficient operation under both outdoor and indoor illumination conditions, generating sufficient electrical power to drive microelectronic devices. Low-bandgap non-fullerene acceptors (NFAs) in OPVs are limited by low open-circuit voltage (VOC) under indoor lighting, restricting their performance. While high-bandgap NFAs can improve indoor power-conversion efficiency (PCE) by elevating VOC, they may often reduce outdoor performance owing to reduced light harvesting. Thus, we developed OPVs using the oligomeric dimerized NFA DYBO, which simultaneously achieved an excellent PCE of 16.7 % under simulated solar illumination and a remarkable maximum power output density (Pmax) of 0.079 and 0.396 mW/cm2 under a 5,200 K LED and halogen lamp (1000 lx), respectively, attributed to elevated VOC and reduced short-circuit current density (JSC) losses. The optimized OPVs demonstrated PCEs nearly equivalent to those of the current state-of-the-art under indoor illumination, with a remarkable Pmax capable of autonomously powering a variety of microelectronic devices. © 2024 Elsevier B.V.