Abstract
In this work, the structural and the optical properties of GaSb epilayers were investigated by using X-ray diffraction (XRD), photoluminescence (PL), and photoreflectance (PR) measurements. All sample were grown by using molecular beam epitaxy, but at various growth temperatures (Ts) from 485 to 540◦C. The XRD results showed that the full width at half maximum (FWHM) of the XRD curves increased with increasing growth temperature due to the formation of defects in the epilayer. The PL results indicated that VGa, GaSb and related defects were formed in the epilayer due to the effects of the growth temperature. The PR spectra of the GaSb epilayers clearly exhibited Franz-Keldysh oscillations (FKOs) caused by the interface electric fields. The inter face electric field between the p-GaSb epilayer and the n+-substrate decreased from 78.4 to 65.6 kV/cm with increasing Ts. We confirmed that the change in the interface electric field was due to the change in the p-type carrier concentration caused by the formation of defect states with increasing Ts from 485 to 540 ◦C.
Original language | English |
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Pages (from-to) | 301-307 |
Number of pages | 7 |
Journal | New Physics: Sae Mulli |
Volume | 68 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2018 |
Keywords
- Defects
- GaSb epilayer
- Growth temperature
- Interface electric field