STUDY OF MISFIT DISLOCATIONS BY EBIC, CL AND HRTEM IN GAAS INGAAS LATTICE-STRAINED MULTIQUANTUM-WELL P-I-N SOLAR-CELLS/

Citation
M. Mazzer et al., STUDY OF MISFIT DISLOCATIONS BY EBIC, CL AND HRTEM IN GAAS INGAAS LATTICE-STRAINED MULTIQUANTUM-WELL P-I-N SOLAR-CELLS/, Materials science & engineering. B, Solid-state materials for advanced technology, 42(1-3), 1996, pp. 43-51
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
43 - 51
Database
ISI
SICI code
0921-5107(1996)42:1-3<43:SOMDBE>2.0.ZU;2-J
Abstract
The location, density and nature of misfit dislocations (MDs) in latti ce-strained multi-quantum well (MQW) structures were investigated by d epth-resolved electron-beam-induced current (EBIC) and cathodoluminesc ence (CL) modes in a scanning electron microscope. A planar network of dark recombination lines due to MDs was observed at the lower and upp er interfaces of the MQW stack. Their density was correlated with the MQW average strain before relaxation, giving information on the equili brium and catastrophic strain relaxation processes which take place at the two MQW stack interfaces. High-resolution transmission electron m icroscopy (HRTEM) showed the location and nature of the MDs at an atom ic level; they are mostly close to the lower MQW stack interface, on a {111} plane constituting glissile-60 degrees dislocations, composed o f two partials including a stacking fault. Comparison of their density with the dark line density indicates that each dark line represents a group of about 9 MDs. Quantitative information on the electrical prop erties of solar cells was obtained by (i) determining the average MD c ontrast at the lower MWQ interface using EBIC gain measurements and (i i) establishing the existence of a strong correlation between the dark current in forward bias and the MD density.