InAs/GaSb Type-II Superlattice Detectors

Abstract

InAs/(In,Ga)Sb type-II strained layer superlattices (T2SLs) have made significant progress since they were first proposed as an infrared (IR) sensing material more than three decades ago. Numerous theoretically predicted advantages that T2SL offers over present-day detection technologies, heterojunction engineering capabilities, and technological preferences make T2SL technology promising candidate for the realization of high performance IR imagers. Despite concentrated efforts of many research groups, the T2SLs have not revealed full potential yet. This paper attempts to provide a comprehensive review of the current status of T2SL detectors and discusses origins of T2SL device performance degradation, in particular, surface and bulk dark-current components. Various approaches of dark current reduction with their pros and cons are presented.

Lattice vibration modes in type-II superlattice InAs/GaSb with no-common-atom interface and overlapping vibration spectra

“…[1] These differences make the electronic structure and vibration spectrum of InAs/GaSb heterostructure more complex and intriguing, and also less well understood. Besides using InAs/GaSb type II superlattices (T2SLs) for IR detection, [2,3] InAs/GaSb heterostructures have lately been explored for fundamental interests, such as exciton condensation, [4,5] quantum spin Hall effect or topologic insulator, [6][7][8][9][10] and graphene-like Dirac fermion. [11] Raman spectroscopy is widely used for studying lattice vibrations and probing electronphonon coupling in semiconductor SLs.…”

Barrier Detectors Versus Homojunction Photodiode

“…The effective energy band-gap, similarly to HgCdTe, can be tailored within a wide range of energy up to 300 meV. The electron effective mass in InAs/GaSb T2SLs does not depend strongly on the energy band-gap value, whereas this dependence is stronger for HgCdTe, reducing contribution of the tunneling currents in the T2SLs structures [23]. At the current status of the T2SLs InAs/GaSb technology, the recombination by deep SRH centers is found to be dominant, as long as the carrier lifetime is taken into consideration (for T > 150 K carrier lifetimes are even lower than 20 ns [24]).…”

Peak separation method for sub-lattice strain analysis at atomic resolution: Application to InAs/GaSb superlattice

“…Epitaxial heterostructures consisting of two or more semiconductors are widely used in micro-and nano-electronics such as transistors 1, 2 , quantum cascade lasers 3 , infrared photodetectors 4 , and light emitting diodes 5 . A critical engineering parameter in designing an epitaxial heterostructure is strain, which arises from the lattice mismatch between dissimilar materials.…”