Aluminium arsenide antimonide, orAlAsSb (AlAs1-xSbx), is a ternaryIII-Vsemiconductor compound. It can be considered as an alloy betweenaluminium arsenide andaluminium antimonide. The alloy can contain any ratio between arsenic and antimony. AlAsSb refers generally to any composition of the alloy.
The room temperature (T = 300K)bandgap andlattice constant of AlAsSb alloys are between those of pureAlAs (a = 0.566 nm, Eg = 2.16 eV) andAlSb (a = 0.614 nm, Eg = 1.62 eV).[2] Over all compositions, the bandgap is indirect, like it is in pure AlAs and AlSb. AlAsSb shares the samezincblende crystal structure as AlAs and AlSb.
AlAsSb can be lattice-matched toGaSb,InAs andInP substrates, making it useful forheterostructures grown on these substrates.
AlAsSb is occasionally employed as a wide-bandgap barrier layer inInAsSb-basedinfrared barrierphotodetectors.[3][4] In these devices, a thin layer of AlAsSb is grown between doped, smaller-bandgap InAsSb layers. These device geometries are frequently referred to as "nbn" or "nbp" photodetectors, indicating a sequence of ann-doped layer, followed by a barrier layer, followed by an n- orp-doped layer. A large discontinuity is introduced into the conduction band minimum by the AlAsSb barrier layer, which restricts the flow of electrons (but notholes) through the photodetector in a manner that reduces the photodetector'sdark current and improves its noise characteristics.[5]
^abVurgaftman, I.; Meyer, J. R.; Ram-Mohan, L. R. (2001). "Band parameters for III–V compound semiconductors and their alloys".Journal of Applied Physics.89 (11):5815–5875.Bibcode:2001JAP....89.5815V.doi:10.1063/1.1368156.
^Fastenau, J. M.; Lubyshev, D.; Nelson, S. A.; Fetters, M.; Krysiak, H.; Zeng, J.; Kattner, M.; Frey, P.; Liu, A. W. K.; Morgan, A. O.; Edwards, S. A.; Dennis, R.; Beech, K.; Burrows, D.; Patnaude, K.; Faska, R.; Bundas, J.; Reisinger, A.; Sundaram, M. (2019). "Direct MBE growth of metamorphic nBn infrared photodetectors on 150 mm Ge-Si substrates for heterogeneous integration".Journal of Vacuum Science & Technology B.37 (3) 031216.Bibcode:2019JVSTB..37c1216F.doi:10.1116/1.5088784.S2CID181448189.
^Soibel, A.; Hill, C. J.; Keo, S. A.; Hoglund, L.; Rosenberg, R.; Kowalczyk, R.; Khoshakhlagh, A.; Fisher, A.; Ting, D. Z.-Y.; Gunapala, S. D. (2015). "Room temperature performance of mid-wavelength infrared InAsSb nBn detectors".Infrared Physics & Technology.70:121–124.Bibcode:2015InPhT..70..121S.doi:10.1016/j.infrared.2014.09.030.
