Quasi-Planar Heterojunction: Enhancing Stability and Practicality in Organic Photovoltaics

With the rapid advancements in the power conversion efficiency (PCE) of organic photovoltaic (OPV) devices, their stability has garnered increasing attention. While material innovation has played a critical role in recent years, the Q-PHJ (quasi-planar heterojunction) architecture offers an alternative approach to device optimization. This article aims to explain how the introduction of the Q-PHJ architecture can mitigate degradation under various conditions without compromising device performance. It begins by illustrating the fundamental mechanisms responsible for the degradation of OPV devices. Following this, the advantages of the Q-PHJ device and the mechanism are explained by introducing our recent work as well as highlighting other researchers’ work in this field. Different aspects and factors such as morphology, the ternary strategy, additive engineering, and vertical distribution were analyzed. The role of material innovation is also discussed. In the end, the feasibility and challenges of applying bilayer and bilayer-dominated devices to industrial manufacturing are analyzed in detail.