Tunable Negative and Positive Photoresponses base on s-SWCNT/Ga2O3 MSM Solar-Blind UV Photodetector

Abstract Tunable photodetectors have shown great applications in visual signal processing, optoelectronic logic circuits, and memory systems. Nevertheless, deep ultraviolet (DUV) tunable photodetectors still face many challenges such as power consumption, integration and photoelectric performance. This work presents a structural innovation by constructing heterostructures between gallium oxide (Ga2O3) and semiconducting single-wall carbon nanotubes (s-SWCNTs) with varying densities, achieving a tunable photoconductive phenomenon in the DUV area. Both positive and negative photoconductivity (PPC and NPC) exhibit excellent performance under a low bias of 200 mV. Notably, the NPC-effect device achieves a current variation rate of 2.6×10 2 , which indicates the potential for advanced optoelectronic applications. The emergence of the NPC photoconductivity can be attributed to the transfer of photogenerated electrons from the Ga2O3 absorption layer to the conductive layer of s-SWCNTs under the built-in electric field. This work demonstrates a promising strategy for developing Ga2O3-based optoelectronic devices with tunable performance.