Growth of Sb-containing Compound Semiconductor Materials and Devices by using Solid Source Molecular Beam Epitaxy
Date Issued
2004
Date
2004
Author(s)
Liu, Po-Wei
DOI
zh-TW
Abstract
In this dissertation, we studied the growth of Sb-containing compound semiconductor materials and devices by using solid source molecular beam epitaxy (SSMBE). GaSb epilayers and GaAsSb/GaAs quantum wells were investigated.
In the study of GaSb epilayer, high quality GaSb epilayers were successfully grown. Free exciton emissions were observed in the low temperature photoluminescence of the GaSb epilayers grown with the optimized growth parameters.
On the growth of GaAsSb/GaAs quantum wells, GaAsSb/GaAs quantum wells were grown on GaAs substrates. Strong photoluminescence intensity was observed in the grown quantum well. By proposing a simple method to exclude the band bending induced blueshift in power dependent photoluminescence, we firstly deduced the flat-band transition energies in the type-II GaAs/GaAsSb quantum wells.With the combination of the photoluminescence analysis of the type-I AlGaAs/GaAsSb quantum wells, we derived the strained band gap of GaAs0.7Sb0.3, which is 1.00±0.01eV. And the determined valence band offset ratios Qv of GaAs/GaAs0.7Sb0.3 and Al0.3Ga0.7As/GaAs0.7Sb0.3 heterostructures are 1.14±0.03 and 0.79±0.03 respectively. Also, we studied the effect of growth interruption at the interfaces with different group V exposure on the optical quality of the GaAsSb/GaAs quantum well. It is found that samples with Sb protection at the interfaces during growth interruption shows better optical quality. These samples also show “S-shape” and “inverse-S shape” characteristics in the PL peak and PL FWHM dependence on temperature. These phenomenon may be due to the co-exist of the localized state related emissions and band-to-band emissions. Sb composition fluctuation and interface roughness may be the reason for the localized state.
Finally, we successfully grew GaAsSb/GaAs double quantum well and single quantum well laser on GaAs substrates by using SSMBE. The lowest threshold current density is 210A/cm2 and the emission wavelength is 1.28um for the double quantum well laser. The lowest threshold current density is 300A/cm2 and the emission wavelength is 1.292um for the single quantum well laser. By studied the spontaneous emission characteristic of the grown laser, we found that the dominate carrier recombination mechanism is radiative recombination. And as temperature increases, the Auger recombination rate increases and dominates the carrier recombination mechanism. The higher carrier density in the type-II quantum well results in higher Auger recombination rate as temperature increases.
Subjects
分子束磊晶
銻化鎵
含銻化合物半導體
銻砷化鎵
GaAsSb
GaSb
Sb-containing compound semiconductor
molecular beam epitaxy
Type
thesis
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