Quantitative mobility spectrum analysis of carriers in GaSb/InAs/GaSb superlattice

Abstract

The authors have investigated electrical transport in a type II GaSb/InAs superlattice grown on GaSb using "quantitative mobility spectrum analysis." Their results indicate that the superlattice contributes a lone electron specie with an ambient temperature mobility of ϳ10 4 cm 2 / V s. Variable temperature studies in the range 50-300 K show that the carrier is associated with an activation energy of 0.27 eV, which is very close to the superlattice band gap.

Impact of temperature and gamma radiation on electron diffusion length and mobility in p-type InAs/GaSb superlattices

“…For the non-irradiated sample, there is an apparent shift in the trend of the minority electron mobility near 120 K shown in Fig. 4 which is characteristic of this T2SLS structure, 7,11,18,25 where a shift in the majority carrier mobility and density was observed for InAs/GaSb SLs with 8/8 and 9/ 9 periodic ML ratios. In those cases, the inflection was attributed to a shift in the dominant scattering mechanism from impurity scattering at low temperatures to phonon scattering at high temperatures.…”

“…(4). The electron mobility for n-type T2SLS with a ML ratio of 9/9, measured in the SL growth plane (l k ) by quantitative mobility spectrum analysis, was found to b $1 Â 10 4 cm 2 /V s at 300 K. 25 However, the anisotropy of minority carrier transport leads to a reduction in electron mobility perpendicular to the growth plane-by as much as a factor of 10, according to B€ urkle et al, where the electron mobility perpendicular to the growth plane (l ? ) of a superlattice structure with InAs/(GaIn)Sb of ML ratio 8/8 was measured to be $1100 cm 2 /V s, though the overall structure is intrinsically different than this case.…”

“…Minority carriers (holes) generated in the n-type region close to the n-p interface [see Figs. 1(a) and 1(b)] do not contribute appreciably to the EBIC signal due to their relatively low mobility (l p ( l e ) 25 and the presence of the InAs/AlSb hole-barrier layer blocks hole transport across the junction. 10 FIG.…”