No CrossRef data available.
Article contents
The Double Donor Issue of the EL2 Defect in GaAs.
Published online by Cambridge University Press: 25 February 2011
Abstract
Photo-induced changes in the infrared (IR) absorption spectrum of the EL2 defect in undoped and lightly alloyed unannealed GaAs materials grown by the liquid-encapsulated Czochralski technique were observed under a monochromatic light irradiation. These changes were attributed to the change of the charge states of EL2. The spectrum which is believed to be due to the charged EL2 exhibits a complex structure with two peaks at 1.07 and 1.32 eV and a shoulder at 0.94 eV. The EL2+/2+ → EL20/+ and EL20/+ → EL2+/2+ transitions were obtained by illuminating the sample with 0.7 ≤ hv ≤ 0.95 eV and 1.3 ≤ hv ≤1.5 eV, respectively. The transformation EL2+/2+ ↔ EL20/+ can be achieved in less than 10 sec and can be repeatedly switched back and forth between the two states. Fourier-transform photoconductivity (FTPC) measurements were performed on a large number of samples both semi-insulating and n-type. Two broad peaks were observed in the FTPC spectra with thresholds at 0.80 and 0.95 eV. The photoquenching and thermal recovery properties of these two peaks are identical to those of EL2. Both IR and FTPC results suggest strongly that EL2 is a double donor.
- Type
- Research Article
- Information
- Copyright
- Copyright © Materials Research Society 1990