Ultraviolet photodetector on flexible polymer substrate based on nano zinc oxide and laser-induced selective metallization

This study fabricated a sensitive and fast response nano zinc oxide (nano-ZnO) ultraviolet (UV) photodetector on flexible polymer substrate via laser direct structuring (LDS) technology. The polystyrene-block-poly-(ethylene-co-propylene) -block-polystyrene copolymer/polypropylene (SEPS/PP) composites incorporated with laser sensitizer of copper hydroxyl phosphate [Cu-2(OH)PO4] were designed as flexible LDS material. X-ray photoelectron spectroscopy analysis confirmed that partial Cu2+ in SEPS/PP composites was reduced to C-u (element copper), which could be used as a catalyst for selective metallization. As a result, the well-defined interdigitated copper electrode was successfully fabricated on polymer substrate. Moreover, the UV photodetector was fabricated through spin -coating nano-ZnO on the interdigitated copper electrode. Photocurrent analysis demonstrated that the obtained UV photodetector exhibited excellent sensitivity and stability. The rise and decay times of the UV photodetector were less than 1 and 0.25 s, respectively. This study provided a guideline to develop electronic devices on flexible polymer materials based on LDS technology.