Enhancing performance of organic photovoltaic and photodetector devices using non-atomically doped ZnO electrodes with superior optical properties

Abstract

Organic photovoltaics (OPVs) and photodetectors (OPDs) are valued for their lightweight, low-cost, and flexible nature, with recent advancements in materials improving device performance. Transparent electrodes play a critical role in these devices, requiring high conductivity and broad spectral transmittance. Conventional indium tin oxide (ITO) faces scarcity issues, spurring exploration of alternatives. Here, we introduce non-atomically doped (NAD) ZnO electrodes with exceptional near-infrared (NIR) transmittance, fabricated via a sol–gel method. We investigate their performance in OPVs and OPDs using three different bulk heterojunction systems. Results reveal ZnO-based devices exhibit heightened short-circuit current density (J_sc) compared to ITO-based ones under solar illumination. Despite slightly lower power conversion efficiency (PCE) due to higher series resistance, NAD-ZnO devices show resilience under LED illumination, outperforming ITO-based devices. Furthermore, photodiode OPD devices utilizing NAD-ZnO electrodes demonstrate significantly enhanced specific detectivity (D*) across all the three systems, indicating their potential for OPD applications. Overall, the superior optical properties and device performance of NAD-ZnO electrodes highlight their promise as replacements for ITO electrodes in organic optoelectronic devices.