| Original Articles |
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Localized and Delocalized States at the Band Gap in Heteroepitaxial GaAs Grown on Si |
| LIANG Jia-chang1;XU Zhou1;LE Xiao-yun2 |
| 1Department of Basic Sciences, Civil Aviation Institute of China, Tianjin 300300
2Institute of Heavy Ion Physics, Peking University, Beijing 100871
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| Cite this article: |
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LIANG Jia-chang, XU Zhou, LE Xiao-yun 1999 Chin. Phys. Lett. 16 132-133 |
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Abstract There exist the interfacial mismatch strains and high density structural defects in heteroepitaxial GaAs grown on Si (GaAs/Si) because of a large misfit of the lattice constants and a large difference in linear thermal expansion coefficient between GaAs and Si materials. Our experiments show that the disordering in GaAs/Si epilayers strongly depends on their growth condition, especially on the concentration ratio [As]/[Ga] and demonstrate that at [As]/[Ga]=20 to 40 the relationship of temperature versus intensities of the dominant photoluminescence (PL) peaks, related to the delocalized states at the band gap of GaAs/Si, satisfies an Arrhenius equation to determine the thermal activation energies of delocalized states and at [As]/[Ga] ≥ 50 the relationship of temperature versus intensities of the dominant PL peaks, related to the localized states, satisfies an equation valid for amorphous semiconductors to determine the characteristic temperatures of localized states reflecting the disorder degree in GaAs/Si epilayers.
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| Keywords:
71.55.Jv
68.55.Ln
78.55.Cr
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Published: 01 February 1999
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| PACS: |
71.55.Jv
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(Disordered structures; amorphous and glassy solids)
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68.55.Ln
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(Defects and impurities: doping, implantation, distribution, concentration, etc.)
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78.55.Cr
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(III-V semiconductors)
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