EBIC STUDIES OF GRAIN-BOUNDARIES

Citation
Db. Holt et al., EBIC STUDIES OF GRAIN-BOUNDARIES, Materials science & engineering. B, Solid-state materials for advanced technology, 42(1-3), 1996, pp. 14-23
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science","Physics, Condensed Matter
ISSN journal
0921-5107
Volume
42
Issue
1-3
Year of publication
1996
Pages
14 - 23
Database
ISI
SICI code
0921-5107(1996)42:1-3<14:ESOG>2.0.ZU;2-Y
Abstract
REBIC is a powerful technique for the study of defects, especially gra in boundaries (GBs), in ill developed, high-resistivity (semi-insulati ng) materials. Ideas for modelling GB REBIC contrast have been propose d but neither quantitatively developed nor applied to details of exper imental contrast. The model of two Schottky barriers back to back for charged boundary (peak and trough) contrast and the high-resistivity b oundary layer model for terraced contrast are spelled out in further d etail here. They are then applied to observations on high-resistivity polycrystalline ZnSe. The models suffice to account for most features observed. The relative doping density on either side of boundaries can be determined by measuring the barrier width as a function of the rev erse bias. The sign of the charge on boundaries can be deduced by obse rving whether the peak or trough occurs on the dark terrace side of a boundary. Observations of the reversal of peak and trough contrast alo ng the length of boundaries indicate that both - very and + very charg ed regions occur. The asymmetry of the peaks and troughs at many terra ced boundaries can be accounted for by the biasing of the Schottky bar riers by the voltage drop across the barrier layer due to the REBIC cu rrent. The significance of the additional information obtainable by (i ) the crystallographic characterization of boundaries by the EBSP tech nique and (ii) studies of the temperature dependence of REBIC contrast is discussed.