MOVPE grown InGaAs/GaAsSb type II quantum well photodiode for SWIR focal plane array

Abstract

Infrared sensors with type II quantum well structure have gained great attention and have shown advanced progress. InGaAs/GaAsSb type II quantum well structures are considered as an attractive material system for realizing low dark current PDs owing to lattice-matching to InP substrate. In this report, we describe successful operation of PIN-PDs with InGaAs/GaAsSb quantum wells grown by metal-organic vapor phase epitaxy (MOVPE). MOVPE method is well-known to have good uniformity which leads to mass-production of focal plane array. Planer type pin-PDs were adopted. The p-n junction was formed in the absorption layer by the selective diffusion of zinc. Electrical and optical characteristics of pin-PDs such as well number dependence of responsivity, were investigated. Dark current was 9.0 μA/cm² at 233 K, which has better uniformity compared to those of MBE sample, and responsivity of 0.8 A/W in SWIR region were obtained. This result indicates that planer photodiode using MOVPE grown InGaAs/GaAsSb type II quantum wells is a promising candidate for consumer applications.