Bi-band detector based on indium selenide and gallium nitride and preparation method thereof

The invention discloses a bi-band detector based on indium selenide and gallium nitride and a preparation method thereof, and mainly solves the problem that simultaneous same-position detection in the prior art is impossible. The bi-band detector comprises a substrate (1), a UV absorption layer (2), an insulating layer (3), an infrared absorption layer (22) and two ohmic electrodes (4, 5), wherein the UV absorption layer is positioned on the substrate, the insulating layer is positioned on the left half plane of the UV absorption layer, a step surface is formed on the right half plane of the UV absorption layer, the left half portion of the infrared absorption layer is positioned on the insulating layer, the right half portion of the infrared absorption layer is positioned on the step surface of the UV absorption layer, the left half portion has a smaller area than the insulating layer, the right half portion has a smaller area than the step surface, a first ohmic electrode is positioned on the infrared absorption layer and has an area greater than the infrared absorption layer and smaller than the insulating layer, and the second ohmic electrode is positioned on the step surface of the UV absorption layer. The bi-band detector allows simultaneous UV and infrared bi-band detection, and improves the performance and detection efficiency of a detection system.