ELECTRICAL-PROPERTIES OF UNDOPED AND SNTE-DOPED GAXIN1-XSB MOLECULAR-BEAM-EPITAXIALLY GROWN ON GAAS

Abstract

Electrical properties of undoped and SnTe-doped GaxIn1-xSb on GaAs grown by molecular beam epitaxy are studied. In the studied composition x from 0.65 to 1, source SnTe is found to be an n-type dopant. The SnTe incorporation efficiency in GaxIn1-xSb is found to have no significant difference from SnTe in GaSb. The fitted ionized impurity concentrations for GaSb increases proportionally with the sample's donor concentrations, suggesting that the charged impurities are introduced through SnTe doping. On the other hand, for GaxIn1-xSb, the fitted ionized impurity concentrations do not vary with the total donor concentration. This suggests that material inhomogeneities or imperfections in GaxIn1-xSb may be the cause of mobility values which are lower than expected. In addition, the V/III beam equivalent pressure (BEP) ratio is found to critically influence the quality of the SnTe-doped ternary layers.