Abstract
The GaSb layers investigated were grown directly on GaAs substrates by molecular beam epitaxy (MBE) using SnTe source as the n-type dopant. By using admittance spectroscopy, a dominant deep level with the activation energy of 0.23-0.26 eV was observed and its concentration was affected by the Sb4/Ga flux ratio in the MBE growth. A lowest deep-level concentration together with a highest mobility was obtained for GaSb grown at 55°C under a Sb4/Ga beam equivalent pressure (BEP) ratio around 7, which should correspond to the lowest ratio to maintain a Sb-stabilized surface reconstruction. In the Hall measurement, an analysis of the temperature-dependent mobility shows that the ionized impurity concentration increases proportionally with the sample's donor concentration, suggesting that the ionized impurity was introduced by an SnTe source. In addition, optical properties of an undoped p-, a lightly and heavily SnTe-doped GaSb layers were studied by comparing their photoluminescence spectra at 4.5K.
Original language | English |
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Pages (from-to) | 1790-1796 |
Number of pages | 7 |
Journal | Journal of Electronic Materials |
Volume | 25 |
Issue number | 11 |
DOIs | |
State | Published - Nov 1996 |
Keywords
- Deep levels
- GaSb Schottky diodes
- Hall measurement
- Photoluminescence (PL)
- SnTe dopants