Quantum-Dot-Based Mid-IR Single-Photon Detector With Self-Quenching and Self-Recovering Operation

A single-photon detector based on an avalanche quantum dot IR photodetector is presented and designed for self-quenching and self-recovering operation at IR wavelength. The device consists of dot layers and resonant tunneling barriers in the absorption region. An additional layer, called the transient carrier buffer, is added to trap the backward holes. For an avalanche process, the accumulation of backward-traveling-avalanche-generated holes leads to a reduction in the electric field of the multiplication region and avalanche gain, and consequently, the detector is quenched. The detector is self-recovered by thermionic emission and tunneling currents. We study the self-quenching and self-recovery performance of the device. A detection efficiency of around 8% is obtained.