caa a22 4500 469091401 CHVBK 20180323133018.0 cr unu---uuuuu 170328e19920901xx s 000 0 eng 10.1007/BF02665547 doi (NATIONALLICENCE)springer-10.1007/BF02665547 Effects of electrode geometry and polarity on the occurrence of negative peaks in optical transient current spectroscopy applied to semi-insulating gallium arsenide [Elektronische Daten] [D. Hui, H. Kato, C. Backhouse, L. Young] Optical transient current spectroscopy (OTCS) involves observing the transient decay of "photoconductivity” and is of interest as a means of characterizing semi-insulating GaAs wafers. We report experimental results which show that the OTCS spectrum and, in particular, the occurrence of negative peaks is strongly dependent on the shape, size and electrode configuration of the specimen, as well as on the magnitude of the applied voltage and (with asymmetric electrodes) its polarity. A negative peak sometimes changes to a current oscillation with increasing voltage, probably indicating field enhanced trapping. Negative peaks may be observed with sandwich structures with a transparent electrode covering the illuminated surface. This shows that a recent proposal that surface states are involved is at least not always correct. It is suggested that several mechanisms can give negative peaks, and probably more than one has done so under the various experimental conditions which have been used. The present work shows that any practical application of OTCS for ingot qualification will be dependent on standardization of specimen geometry, electrodes and operating parameters. TMS, 1992 GaAs nationallicence optical transient current spectroscopy nationallicence deep levels nationallicence Hui D. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut Kato H. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut Backhouse C. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut Young L. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut Journal of Electronic Materials Springer-Verlag 21/9(1992-09-01), 901-909 0361-5235 21:9<901 1992 21 11664 https://doi.org/10.1007/BF02665547 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02665547 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hui D. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut NATIONALLICENCE 700 1- Kato H. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut NATIONALLICENCE 700 1- Backhouse C. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut NATIONALLICENCE 700 1- Young L. Electrical Engineering Department, University of British Columbia, V6T 1Z4, Vancouver, B.C., Canada aut NATIONALLICENCE 773 0- Journal of Electronic Materials Springer-Verlag 21/9(1992-09-01), 901-909 0361-5235 21:9<901 1992 21 11664 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer