Type-II Superlattice Infrared Photodiodes

doi:10.1117/3.2278814.ch5

Book: Antimonide-based Infrared Detectors: A New Perspective

Author(s): Antoni Rogalski, Małgorzata Kopytko, Piotr Martyniuk

Published: 2018

https://doi.org/10.1117/3.2278814.ch5

Author Affiliations +

Abstract

Many types of optoelectronic devices can be significantly enhanced through the introduction of quantum confinement in reduced-dimensionality heterostructures. This was the main motivation for the study of superlattices as alternative infrared detector materials. The HgTe/CdTe SL system proposed in 1979 was the first from a new class of quantum-sized structures for IR photoelectronics, which was proposed as a promising new alternative structure for the construction of LWIR detectors to replace those of HgCdTe alloys. It was anticipated that superlattice infrared materials would have several advantages over bulk HgCdTe for these reasons: • a higher degree of uniformity, which is importance for detector arrays; • smaller leakage current due to the suppression of tunneling (larger effective masses) available in superlattices; and • lower Auger-recombination rates due to substantial splitting of the light- and heavy-hole bands and increased electron effective masses.