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Anomalous circular photogalvanic effect in p-GaAs.
Optics Express
|May 14, 2021
Summary
Circularly polarized light generates spin-polarized carriers in p-GaAs, creating a detectable current via the anomalous circular photogalvanic effect (ACPGE). Doping concentration influences ACPGE signals, explained by impurity models.
Area of Science:
- Condensed Matter Physics
- Semiconductor Spintronics
Background:
- The anomalous circular photogalvanic effect (ACPGE) involves generating charge currents from circularly polarized light.
- Spin-polarized carriers are crucial for spintronic devices.
Purpose of the Study:
- Investigate ACPGE in p-GaAs at room temperature.
- Analyze the influence of doping concentration on ACPGE signals.
- Elucidate the role of doping impurities in ACPGE.
Main Methods:
- Experimental observation of ACPGE in 2 μm thick p-GaAs.
- Systematic variation of doping concentration.
- Theoretical analysis using extrinsic and intrinsic impurity models.
Main Results:
- ACPGE was observed in p-GaAs at room temperature.
- Normalized ACPGE signals initially increased then decreased with doping concentration.
- Both extrinsic and intrinsic models successfully explained the observed doping dependence.
Conclusions:
- Doping impurities play a significant role in modulating ACPGE in p-GaAs.
- The observed doping dependence of ACPGE is consistent with established theoretical models.
- This study provides insights into spin-current generation mechanisms in semiconductors.
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