Carrier compensation and scattering mechanisms in p-GaSb

Abstract

The hole transport properties of gallium antimonide with various degrees of tellurium compensation have been investigated in the temperature range of 4.2-300 K. For the undoped GaSb, the p-type conductivity arises from a doubly ionizable native defect V Ga Ga Sb. In the Te compensated samples, apart from the Te-donor level and the V Ga Ga Sb center, an acceptor level resulting from complexation of V Ga Ga Sb with Te Sb has been found. This acceptor level lies ϳ70 meV above the valence band edge. The concentration of this center depends on the melt composition and the level of Te present in the melt during growth of crystals. Most interestingly, at very low level of Te concentration, an additional triple native acceptor ͑V Ga Ga Sb V Ga ͒ has also been observed. With the increase in Te concentration, the mobility decreases and a shift in the mobility peak to higher temperature is observed. The low-temperature mobility is limited by ionized impurity scattering. At higher temperatures, the scattering mechanisms depend on Te concentration in the sample. In this regime, significant contributions from acoustic, nonpolar optical, and polar optical phonon scattering are observed for samples with low levels of Te. In contrast, the impurity scattering dominates even at room temperature for highly compensated crystals.

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

“…5. 10 Moreover, the ambient temperature value of mobility obtained from present measurements ͑ϳ10 4 cm 2 / V s͒ matches with that reported in the literature. 10 We have noted that QMSA ϳ T −1.31 , in good agreement with the exponent "−1.4" reported earlier.…”

“…͑1͒, is plotted against temperature in Fig. 10 We have noted that QMSA ϳ T −1.31 , in good agreement with the exponent "−1.4" reported earlier. A steeper drop at low temperatures is a result of ionized impurity scattering, 9 while gradual decrease at higher temperatures ͑T Ͼ 100 K͒ is due to phonon scattering.…”

Analysis of low‐temperature data of Hall‐effect measurements on p‐type InP using a small‐polaron theory

“…, however, the plot point for the most heavily Zn‐doped sample (B276) deviates from the square dependence extrapolated from the plot points for the other two Zn‐doped samples. In p‐type GaSb, the second acceptor level with an activation energy of 20–30 meV has often been found and has been attributed to a native defect . Also in p‐type InP, the second acceptor level may be attributed to such a native defect.…”

Influence of Growth Conditions and Doping on Physical Properties of Gallium Antimonide Single Crystals

“…Following above steps, hole concentration has been lowered signicantly beneath the value Hole concentration value in undoped GaSb strongly depends on growth conditions and should be kept as low as possible, but in the same time hole mobility should stay high. Undoped GaSb purity can be conrmed by low-temperature Hall measurements [13,14]. Signicant dierences in low-temperature hole mobility are shown in By now very little is known about Zn-doped CZ-grown GaSb.…”