Ultra-broadband UV-VIS-SWIR InGaAs focal plane arrays via n-InP contact layer removal

Abstract

We present ultra-broadband ultraviolet (UV)‒visible light (VIS)‒short wavelength infrared (SWIR) 640×512 15 μm InGaAs focal plane arrays (FPAs) by removing the n-InP contact layer in the active area and reserving the InP contact layer around the pixels for n contact, creating incident light to be directly absorbed by the In0.53Ga0.47As absorption layer. In addition, the optical absorption characteristics of InGaAs FPAs with and without an n-InP contact layer are studied theoretically. Benefiting from n-InP contact layer removal, the spectral response is extended to the range of 200–1700 nm, and the quantum efficiency is higher than 45% over a broad wavelength range of 300‒1650 nm. Imaging capability of InGaAs FPAs without an n-InP contact layer has been demonstrated, which has proved the feasibility for the applications of InGaAs detectors in these three bands.