Self-Powered Ultraviolet Photodetectors Based on Conductive Polymers/GaO Heterojunctions: A Review.

Self-powered ultraviolet photodetectors hold significant potential for diverse applications across both military and civilian fields. Owing to its wide bandgap, high electron mobility, and adaptability to various substrates, gallium oxide (GaO) serves as a crucial material for fabricating self-powered ultraviolet photodetectors. Photodetectors based on p-n heterojunctions of conductive polymers and gallium oxide have great application potential benefiting from unique advantages of conductive polymers. This review provides an extensive overview of typical ultraviolet photodetectors based on conductive polymer/gallium oxide heterojunctions, focusing on the physical structure, fabrication process, and photoelectric properties of heterojunction devices formed by GaO with conductive polymers like polythiophene, polyaniline, and polycarbazole, etc. Different conductive polymers yield varying performance improvements in the fabricated devices: polythiophene/GaO devices exhibit high conductivity and flexible bandgap tuning to meet diverse wavelength detection needs; PANI/GaO devices feature simple fabrication and low cost, with doping control to enhance charge carrier transport efficiency; polycarbazole/GaO devices offer high thermal stability and efficient hole transport. Among them, the polythiophene/GaO device demonstrates the most superior overall performance, making it the ideal choice for high-performance GaO-based photodetectors and a representative of such research. This review identifies the existing technical challenges and provides valuable insights for designing more efficient GaO/conductive polymer heterojunction photodetectors.