Low Dark Current SWIR Photodiode with InGaAs/GaAsSb Type II Quantum Wells Grown on InP Substrate

摘要

We have developed a PIN photodiode with a type II quantum well structure, which can operate in the short wavelength region up to 2.5 μm. This photodiode will make uncooled operation possible. The absorption layer consisting of 250 pair-InGaAs(5nm)/ GaAsSb(5nm) quantum well structures was grown on InP substrates by solid source MBE method. The p-n junctions were formed in the absorption layer by the selective diffusion of zinc. Dark current density was 0.92 mA/cm2 , which was smaller than that of a conventional HgCdTe detector. The responsivity at 2.2 μm was 0.6A/W.