Atomistic Transport Modeling, Design Principles, and Empirical Rules for Low-Noise III-V Digital-Alloy Avalanche Photodiodes

Abstract

A series of $I\phantom{\rule{0}{0ex}}I\phantom{\rule{0}{0ex}}I\ensuremath{-}V$ alloy-based avalanche photodiodes are recently seen to demonstrate superior performance such as low excess noise, but the origin of such behavior is not completely understood. The authors use atomistic modeling of the material and transport properties to deconstruct the underlying physical mechanisms, which are attributed to a combination of engineered minigaps, increased effective mass, and spin-orbit coupling. These attributes selectively limit the ionization rate of one carrier type, and are simplified here into a set of inequalities that could potentially be useful for the design of future high-performance avalanche photodiodes.