Highly Responsivity of UV Photodetector Based on ZnO/PEDOT:PSS/CsCu ₂ I ₃ Heterojunction

Perovskite materials have been widely developed for use in photodetectors due to their unique advantages, but most perovskites contain environmentally harmful lead. Herein, spin-coating is employed to fabricate nontoxic Cu-based perovskite films. By constructing a CsCu 2 I 3 and ZnO heterojunction and incorporating a PEDOT:PSS hole transport layer, the ZnO/PEDOT:PSS/CsCu 2 I 3 UV photodetector demonstrates a significantly enhanced spectral range and improved optoelectronic performance compared to a CsCu 2 I 3 photodetector. Specifically, the photocurrent of ZnO/PEDOT:PSS/CsCu 2 I 3 is enhanced by 3 orders of magnitude, reaching 1.43 × 10 –4 A, and the responsivity is improved 57-fold to 0.67 A/W. This achievement provides an effective route for fabricating highly responsive Cu-based perovskite photodetectors.