Background limited long wavelength infrared type-II InAs/GaSb superlattice photodiodes operating at 110 K

Abstract

The utilization of the P+-π-M-N+ photodiode architecture in conjunction with a thick active region can significantly improve long wavelength infrared type-II InAs/GaSb superlattice photodiodes. By studying the effect of the depletion region placement on the quantum efficiency in a thick structure, we achieved a topside illuminated quantum efficiency of 50% for an N-on-P diode at 8.0 μm at 77 K. Both the double heterostructure design and the application of polyimide passivation greatly reduce the surface leakage, giving an R0A of 416 Ω cm2 for a 1% cutoff wavelength of 10.52 μm, a Shot–Johnson detectivity of 8.1×1011 cmHz/W at 77 K, and a background limited operating temperature of 110 K with 300 K background.

Study of Surface Treatments on InAs/GaSb Superlattice LWIR Detectors

“…Some attempts to utilize a wet etch for restoration of damage produced during the dry etching of mesa sidewalls have been reported. 17,21 However, no comparison between sidewall profile characteristics obtained after conventional (plasma-assisted) etch, chemical etch, and combinations of both etches has yet been provided.…”

Dots, QWISPs, and BIRDs

“…Superlattices or alloys build from the InAs/GaSb/AlSb material system can also be tailordesigned to build matching unipolar barriers. Examples of the broken-gap superlattice based BIRDs are the superlattice nBn [31] and the superlattice DH [32].…”

Dark current mechanism of unpassivated mid wavelength type II InAs/GaSb superlattice infrared photodetector

“…The bulk current is considered to be related to some factors such as the defects and the doping concentration inside the material. One way to reduce the bulk current is to use the so-called barrier engineering method by adding some barrier layers into the SL structure [16][17][18][19]. The surface current, on the other hand, is related to some surface effects caused by the dangling bonds and the fast interface states etc.…”