PHOTO TRANSISTOR

Abstract

A phototransistor includes a substrate, a gate layer, a dielectric layer, an active layer, a source and a drain, and a light absorption layer. The gate layer is disposed on a top of the substrate, and the dielectric layer is disposed on a top of the gate layer. The active layer has a first bandgap and is disposed on a top of the dielectric layer, and the source and the drain are disposed on a top of the active layer. The light absorption layer has a second bandgap and is capped on the active layer, and the second bandgap is smaller than the first bandgap.