DX centers in III-V semiconductors under hydrostatic pressure. [GaAs:Si; InP:S]
DX centers are deep level defects found in some III-V semiconductors. They have persistent photoconductivity and large difference between thermal and optical ionization energies. Hydrostatic pressure was used to study microstructure of these defects. A new local vibrational mode (LVM) was observed in hydrostatically stressed, Si-doped GaAs. Corresponding infrared absorption peak is distinct from the Si[sub Ga] shallow donor LVM peak, which is the only other LVM peak observed in our samples, and is assigned to the Si DX center. Analysis of the relative intensities of the Si DX LVM and the Si shallow donor LVM peaks, combined with Hall effect and resistivity indicate that the Si DX center is negatively charged. Frequency of this new mode provides clues to the structure of this defect. A pressure induced deep donor level in S-doped InP was also discovered which has the properties of a DX center. Pressure at which the new defect becomes more stable than the shallow donor is 82 kbar. Optical ionization energy and energy dependence of the optical absorption cross section was measured for this new effect. Capture barrier from the conduction band into the DX state were also determined. That DX centers can be formed in InP by pressure suggests that DX states should be common in n-type III-V semiconductors. A method is suggested for predicting under what conditions these defects will be the most stable form of the donor impurity.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6710951
- Report Number(s):
- LBL-33379; ON: DE93007701
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Local-vibrational-mode spectroscopy of DX centers in Si-doped GaAs under hydrostatic pressure
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GALLIUM ARSENIDES
CRYSTAL DEFECTS
INDIUM PHOSPHIDES
ABSORPTION SPECTRA
DOPED MATERIALS
IMPURITIES
IONIZATION
N-TYPE CONDUCTORS
PRESSURE EFFECTS
SILICON ADDITIONS
SULFUR ADDITIONS
VERY HIGH PRESSURE
VIBRATIONAL STATES
ALLOYS
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL STRUCTURE
ENERGY LEVELS
EXCITED STATES
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
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SEMICONDUCTOR MATERIALS
SILICON ALLOYS
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360602* - Other Materials- Structure & Phase Studies