Resonant tunneling diode photodetector with nonconstant responsivity

Resonant tunneling diode with an In 0.53 Ga 0.47 As absorption layer is designed for light detection at 1550 nm. The responsivity of the detector is simulated by solving the Tsu–Esaki equation. The simulation results show that the responsivity of the detector is nonconstant. It decreases with the increment of the power density of the incident light. Samples of the detector are fabricated by molecular beam epitaxy. The experimental results show that the responsivity increases while the power density of the incident light decreases which agree with the simulation results. The responsivity reaches 4.8×10 8 A/(W/μm 2 ) at room temperature and 5.0×10 9 A/(W/μm 2 ) at 77 K when the power density of the incident light is 1×10 −13 W/μm 2 .