Organic solar cells based on a Cu₂O/FBT-TH4 anode buffer layer with enhanced power conversion efficiency and ambient stability

An organic–inorganic integrated hole transport layer (HTL) composed of a semicrystalline 5,6-difluorobenzothiadiazole based conjugated polymer FBT-TH4 and cuprous oxide (Cu₂O) is successfully incorporated into conventional structured organic solar cells (OSCs). The optimized OSCs show a high power conversion efficiency of up to 9.56% and good stability under ambient conditions. The results highlight the potential application of this organic–inorganic integrated HTL in OSCs.