A high-efficiency low-noise signal amplification mechanism for photodetectors

摘要

Recently we discovered a signal amplification mechanism to amplify photocurrent with high efficiency and low noise. Unlike conventional impact ionization used in avalanche photodetectors, the new amplification mechanism can produce high (>1000) gain with very low excess noise factor (<2 for Si) under very low bias voltage (3 V). The new amplification mechanism offers a promising solution for light detection for Si-photonics, imaging, and sensing. Physics of this mechanism lies in two subsequent processes i) Auger excitation between mobile and highly localized electrons and ii) electron-phonon coupling. In this paper, experimental results are supported by the proposed physical model using simulations within density functional theory (DFT) framework.