Midwave infrared type-II InAs∕GaSb superlattice detectors with mixed interfaces

Abstract

We report the growth and fabrication of midwave infrared InAs/ GaSb strain layer superlattice ͑SLS͒ detectors. Growth of alternate interfaces leads to a reduced strain between the GaSb buffer and SLS ͑⌬a ʈ / a =−5ϫ 10 −4 ͒, enabling the growth of active regions up to 3 m ͑625 periods͒. The structural, optical, and electrical properties of the active region were characterized using x-ray crystallography and photoluminescence, respectively. p-in detectors were grown using 625 periods of 8 ML ͑monolayer͒ InAs/8 ML GaSb as the active region. The cutoff for the detectors was 4.6 m with a conversion efficiency of 32% at V b = −0.2 V. Detectivity was obtained using noise power spectral density measurements under 300 K 2 field of view illumination and was equal to 5.2ϫ 10 10 and 3 ϫ 10 10 cm Hz 1/2 /W ͑V b = −0.02 V, T =80 K͒ in the white noise and 1 / f noise limit ͑at 50 Hz͒.

Passivation of long-wave infrared InAs/GaSb strained layer superlattice detectors

“…Growth details have been reported elsewhere [18]. The p-i-n detector structure was formed by $2.8 lm (395 periods) 14 monolayers (MLs) InAs/7 MLs GaSb SLS non-intentionally doped (n.i.d.)…”

Heterostructure engineering in Type II InAs/GaSb strained layer superlattices

“…Details of the growth conditions have previously been reported [16]. The growth substrates were n-type (Te-doped) GaSb (100) epiready substrates.…”

“…We have investigated the effect of a variable background doping concentration in the absorber region of an nBn type-II InAs/GaSb superlattice infrared detector. The doping concentrations were 5x10 16 cm -3 (non-intentionally doped, n.i.d. ), 1.4x10 17 cm -3 , 4.0x10 17 cm -3 , and 3.5x10 18 cm -3 .…”

InAs/GaSb strained layer superlattice detectors with nBn design

“…Growth details have been reported elsewhere [17]. The device structure consists of $1 lm 10 monolayers (ML) InAs/10 MLs GaSb SLS (170 periods) absorber grown on top of $0.36 lm thick n-type contact layer (composed by the SLS with the same composition and thickness but with Si-doped InAs layers).…”