1. Surface photovoltage effects onp-GaAs (100) from core-level photoelectron spectroscopy using synchrotron radiation and a laser
- Author
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Minoru Itoh, Masao Kamada, J. Murakami, Yasuo Fujii, Senku Tanaka, and Sam D. Moré
- Subjects
Band bending ,Materials science ,X-ray photoelectron spectroscopy ,law ,Surface photovoltage ,Synchrotron radiation ,Atomic physics ,Nanosecond ,Photoelectric effect ,Laser ,Spectral line ,law.invention - Abstract
The surface photovoltage (SPV) effect on laser-excited p-GaAs (100) has been investigated using core-level photoelectron spectroscopy with synchrotron radiation (SR). The energy shift of the $\mathrm{Ga}3d$ photoelectrons due to the SPV effect was remarkably dependent on the sample temperature and the laser photon flux. The dependence in each case was well interpreted on the basis of a simple SPV formula derived from the band-bending scheme with excess photocarriers. The magnitude of the band bending was about 0.8 eV for clean p-GaAs (100) surfaces having no electrodes. Similar core-level shifts were observed in the $\mathrm{Ga}3d$ and $\mathrm{Cs}4d$ spectra of Cs/GaAs (100), indicating an unpinned behavior of the electronic states of the Cs surface layer. The time response of the SPV effect was also investigated in the nanosecond range using a pump-probe method with SR and the laser.
- Published
- 2001