| Abstract |
| The photoreflectance (PR) method is advantageous in that it is more convenient to use at low temperature and high temperature than electroreflectance (ER) due to the modulation of the electric field. This is caused by the recombination of the surface state charge and the minority carriers generated by the laser light. For this reason, PR makes it easier to study the microstructure of semiconductors using non-contact and non-destructive characteristics on the surface of the sample. The position of the Fermi level of the semiconductor can also be determined and the surface electric field can be optically determined. We studied the photoreflectance characteristics of the Al0.21Ga0.79As/GaAs heterostructure. We observed the A region (1.49∼1.53 eV) in the PR spectra by varying the pumping intensity in the sample. The room temperature PR spectra exhibited A region oscillations. This was found to be due to the increasing electric field intensity.
(Received February 3, 2017; Accepted March 3, 2017) |
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| Key Words |
| AlGaAs, GaAs, photoreflectance, intensity |
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