Controlled synthesis of GaSe microbelts for high-gain photodetector induced by the electron trapping effect

GaSe microbelts was successful synthesized by using Ga/Ga2Se3 as the mixture precursors, where excess Ga was required to serve as the metal catalyst. Meanwhile, a spontaneously oxidized surface amorphous oxide (GaOx) layer was presented, which induced a built-in electric field perpendicular to the surface. Benefiting from this effect, the GaSe microbelt-based photodetector has attained a high responsivity of ~3866 AW-1 and a photoconductive gain up to ~1.06×104. This study sheds light on the controlled synthesis of microstructures and provides a device design concept for high-performance micro/nano optoelectronics.