Demonstration of dual gain mechanism in an InGaAs/InAlAs superlattice photodiode

Abstract

A high‐gain photodiode in which the internal gain can result from either potential barrier lowering or mass filtering action, depending on device geometry and bias conditions, is proposed and demonstrated. The photodiode structure is similar to a modulated barrier diode and uses In0.53Ga0.47As and InGaAs/InAlAs superlattice absorption regions. The superlattice helps to reduce the dark current and aids in mass filtering. The devices reported here were made with multilayered InP‐based materials grown by molecular beam epitaxy and exhibit responsivity as high as 1000 A/W.