Abstract
Organic solar cells (OSCs) offer a promising low-cost and flexible alternative to conventional photovoltaic technologies; however, their performance remains limited by inefficient charge transport and carrier recombination losses. In this work, we present a novel nanoarrayed hole-transport layer (HTL) based on Cu₂ O/CuSCN heterostructures fabricated via a two-step electrodeposition process. Vertically aligned Cu₂O nanocrystals were grown on CuSCN films, forming a nanostructured charge-extraction framework with enhanced interfacial contact and potentially reduced carrier transport distances. The morphology and properties of the films were systematically tuned by controlling the electrochemical parameters, enabling the formation of well-defined nanoarchitectures. Photoelectrochemical measurements revealed enhanced interfacial photocurrent and improved charge-extraction characteristics of the composite structures compared with the corresponding single-layer films. When integrated into PTB7-th:PCBM-based OSCs, the nanoarrayed HTL substantially improved device performance, increasing the open-circuit voltage from 0.62 to 0.84 V, the shortcircuit current density from 7.99 to 11.8 mA cm⁻ ², and the power conversion efficiency from 2.76% to 5.59%. These improvements are attributed to more efficient charge collection and suppressed recombination enabled by the nanoarray architecture. This study demonstrates a low-temperature electrodeposition strategyfor engineering advanced HTLs and highlights the potential of nanoarrayed Cu₂O/CuSCN heterostructures for future organic and hybrid photovoltaic devices.