Post-growth annealing of type-II GaSb/GaAs quantum dots grown with different V/III ratios

作者：Polojarvi Ville^*; Gubanov Alexander; Schramm Andreas; Koskinen Riku; Paajaste Jonna; Salmi Joel; Suomalainen Soile; Guina Mircea

来源：Materials Science and Engineering B-Solid State Materials for Advanced Technology, 2012, 177(13): 1103-1107.

DOI：10.1016/j.mseb.2012.05.017

• Quantum dots
• GaSb
• Thermal annealing
• Photoluminescence
• Molecular beam epitaxy
• III-V semiconductors

We report the influence of V/III beam-equivalent-pressure ratios and post-growth annealing on the photoluminescence of GaSb quantum dots grown on GaAs(1 0 0) by molecular beam epitaxy. Increasing the V/III beam-equivalent-pressure ratio from 3 to 5 and then to 7 results in decreased photoluminescence intensity and redshifts the photoluminescence wavelength. The post-growth annealing blueshifts the quantum dot photoluminescence emission and decreases the full-width-at-half-maximum of the photoluminescence peak when annealing temperature is increased above 800 degrees C. The blueshift behavior is found to be independent on the V/III ratios indicating a similar atomic interdiffusion mechanism for all investigated samples regardless of the quantum dot properties. The photoluminescence intensities of the three samples experience an increase after moderate annealing. Whereas the intensity of the sample with the highest V/III ratio further increases, the intensity of the sample with lower V/III ratios decreases again upon higher annealing steps above 900 degrees C. Furthermore, temperature- and power dependent photoluminescence measurements are performed on as-grown and 870 degrees C annealed samples with V/III ratios of 3 and 7 in order to study the reduced quantum dot confinement in more detail.

• 出版日期2012-8-1