ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Photoreflectance (PR) spectroscopy has been used to study the surface Fermi level in GaAs by taking account of photovoltaic properties at the semiconductor surface. The PR signal amplitude ||ΔR/R|| is proportional to a modulating photovoltage Vm generated by a modulation light irradiation. To modify the surface potential, the sample was irradiated by a third perturbing light, i.e., a continuous bias light Pb, together with the modulation light. The modulation light power dependence of ||ΔR/R|| is extremely sensitive to bias light intensity, surface Fermi level, and temperature. From the analysis of the temperature dependence of ||ΔR/R|| on modulation-light power, the surface Fermi level of 0.47±0.09 eV below the conduction band was determined for a molecular beam epitaxially-grown GaAs(100).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.347023
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