Electrical and magnetotransport in AlxIn1-xAsySb1-y/GaSb multilayers

Multilayer structures of AlxIn1-xAsySb1-y/GaSb (0.37 less than or equal to x less than or equal to 0.43, 0.50 less than or equal to y less than or equ al to 0.52), grown by molecular beam epitaxy on GaSb(100) substrates, have been characterized using variable-temperature Hall and Shubnikov-de Haas (S dH) techniques. For nominally undoped structures both p- and n-type conduct ivity was observed. The mobilities obtained were lower than those predicted by an interpolation method using the binary alloys and, therefore, a detai led analysis of mobility versus temperature data was performed to extract t he appropriate scattering mechanisms. For p-type samples, the dominant mech anism was ionized impurity scattering at low temperatures (T < 70 K) and po lar optical phonon at higher temperatures (T > 90 K). For n-type, ionized i mpurity scattering was predominant at low temperatures (T < 70 K), and elec tron-hole scattering dominated for both the intermediate- and high-temperat ure range (T > 100 K). SdH measurements were made on the higher-mobility sa mples. Analyses of the SdH data indicate the presence of two-dimensional ca rrier confinement consistent with energy subbands in shallow GaAszSb1-z pot ential wells.