Terahertz detector with efficient conversion and preparation method thereof

The invention relates to an efficient conversion terahertz detector and a preparation method, the terahertz detector comprises a substrate layer, a composite buffer layer, a channel layer, a barrier layer, a gate electrode, a source electrode and a drain electrode, the back surface of the substrate layer is convex so as to focus terahertz waves incident from the back surface; the composite buffer layer, the channel layer and the barrier layer are sequentially stacked on the upper surface of the substrate layer; the gate electrode, the source electrode and the drain electrode are all located on the barrier layer, and the gate electrode is located between the source electrode and the drain electrode. According to the embodiment of the invention, the substrate layer in the terahertz detector is arranged to be in the convex shape for focusing the terahertz waves, so that the efficiency of the detector for receiving the terahertz waves incident from the back surface is improved, various indexes of the terahertz de