Back to Search
Start Over
Structural and optical properties of sulfur passivated epitaxial step-graded GaAs1-ySby materials.
- Source :
- AIP Advances; Nov2018, Vol. 8 Issue 11, pN.PAG-N.PAG, 18p
- Publication Year :
- 2018
-
Abstract
- The impact of bulk and surface defect states on the vibrational and optical properties of step-graded epitaxial GaAs<subscript>1-y</subscript>Sb<subscript>y</subscript> (0 ≤ y ≤ 1) materials with and without chemical surface treatment by (NH<subscript>4</subscript>)<subscript>2</subscript>S was investigated. Tunable antimony (Sb) composition GaAs<subscript>1-y</subscript>Sb<subscript>y</subscript> epitaxial layers, grown by solid source molecular beam epitaxy (MBE), were realized on GaAs and Si substrates by varying key growth parameters (e.g., Sb/Ga flux ratio, growth temperature). Raman and photoluminescence (PL) spectroscopic analysis of (NH<subscript>4</subscript>)<subscript>2</subscript>S-treated GaAs<subscript>1-y</subscript>Sb<subscript>y</subscript> epitaxial layers revealed composition-independent Raman spectral widths and enhanced PL intensity (1.3×) following (NH<subscript>4</subscript>)<subscript>2</subscript>S surface treatment, indicating bulk defect-minimal epitaxy and a reduction in the surface recombination velocity corresponding to reduced surface defect sites, respectively. Moreover, quantification of the luminescence recombination mechanisms across a range of measurement temperatures and excitation intensities (i.e., varying laser power) indicate the presence of free-electron to neutral acceptor pair or Sb-defect-related recombination pathways, with detectable bulk defect recombination discernible only in binary GaSb PL spectra. In addition, PL analysis of the short- and long-term thermodynamic stability of sulfur-treated GaAs<subscript>1-y</subscript>Sb<subscript>y</subscript>/Al<subscript>2</subscript>O<subscript>3</subscript> heterointerfaces revealed an absence of quantifiable atomic interdiffusion or native oxide formation. Leveraging the combined Raman and PL analysis herein, the quality of the heteroepitaxial step-graded epitaxial GaAs<subscript>1-y</subscript>Sb<subscript>y</subscript> materials can be optimized for optical devices. [ABSTRACT FROM AUTHOR]
- Subjects :
- EPITAXY
PASSIVATION
OPTICAL properties
Subjects
Details
- Language :
- English
- ISSN :
- 21583226
- Volume :
- 8
- Issue :
- 11
- Database :
- Complementary Index
- Journal :
- AIP Advances
- Publication Type :
- Academic Journal
- Accession number :
- 133317893
- Full Text :
- https://doi.org/10.1063/1.5028133