Article
Raman and FTIR Spectroscopy of GaSb and AlxGai.xSb Alloys with Nanometric Thickness Grown at Low Temperatures by Liquid Phase Epitaxy
Autor
Rojas López, Marlon
Institución
Resumen
GaSb and AlxGai.xSb thin layers were grown on (001) oriented GaSb substrates by liquid phase epitaxy technique at low
temperatures. Until now, there are no previous reports on the growth of this alloy at temperatures lower than 400 °C. The layers
were grown from 400 to 250 °C for the ternary layers, and at 200°C for the binary layers using a supercooling process of 10 °C
and a cooling rate of 0.5 °C/min. In addition to that, ternary AlxGai.xSb layers were prepared at 250 °C for several contact times
1, 5, 10, 40 and 80 minutes, and something similar was done for binary GaSb layers, with contact times of 7.5, 15, 30, 60 and
120 minutes. Infrared reflectance results show the presence of single mode spectra for GaSb layers and two mode spectra for
AlxGai.xSb layers corroborating the growth of the alloys, whereas Raman scattering results show also the single and two mode
behaviors of the GaSb and AlxGai.xSb layers respectively. In ternary layers Raman bands, such as LO-GaSb like mode undergo
a shift to low energies with growth temperature and with contact time. The results suggest a greater incorporation of Al atoms in
the layer for smaller contact times that with greater contact times, and also for high temperatures that with low temperatures.