XBn and XBp barrier detectors offer diffusion-limited dark current and high operating temperatures. Type II superlattices (T2SLs) based on either InAs/GaSb or InAs/InAsSb are ideal for their fabrication for two important reasons. First, their bandgaps can be matched to the mid-wave infrared (MWIR) or long-wave infrared (LWIR) transparency ranges of the atmosphere, and second, their mini-band edges can be designed to create a large barrier for majority carriers and a negligible barrier for minority carriers, two requirements necessary for successful device operation. The main challenges are a short lifetime for both types of minority carrier in InAs/GaSb T2SLs, and non-metallic hole conductivity in both types of T2SL leading to a very low hole mobility. In this work we demonstrate how these challenges can be met, by exploiting high electron mobilities in InAs/GaSb T2SLs, and a long Auger-limited hole lifetime in the gallium-free T2SL for doping levels below 1015 cm−3. Full MWIR focal plane array (FPA) operating temperatures are presented close to 130 K, and robust LWIR FPA operation is demonstrated at 77 K.
|Number of pages||6|
|Journal||Journal of Electronic Materials|
|State||Published - Sep 2022|
Bibliographical noteFunding Information:
The authors acknowledge technical support from Mr. I. Bogoslavski, Mr. Y. Caracenti, Mr. A. Franco, Mr. M. Grinberg, Mr. S. Greenberg, Mr. D. Gur, Ms. N. Hazan, Ms. L. Krivolapov, Ms. M. Menahem, Ms. H. Moshe, Mr. Y. Osmo, Mr. E. Sandik, and Ms. H. Schanzer, and who have all contributed to the successful growth, processing, packaging and characterization of the materials and devices.
© 2022, The Minerals, Metals & Materials Society.
- background-limited performance
- barrier detector
- type II superlattice