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A complete study of the free and bound exciton photoluminescence (PL) line temperature behavior on high-quality 4H-SiC epitaxial crystals is presented. At low temperatures (T≤ 60 K), in the PL spectra the lines related to both free exciton (FE) and nitrogen-bound exciton (N-BE) are visible. At higher temperatures are present exclusively FE emission lines; their intensity decreases as the sample temperature increases, and they are no longer visible at about 140 K. The FE and N-BE temperature behavior is studied and the activation energies of the phenomena (growth and quenching) associated with the low-temperature photoluminescence (LTPL) lines are determined. Some possible interpretations of the obtained values are proposed, and a kinetic model describing the recombination processes that produce luminescence lines is suggested.
IOP Publishing
Publication date: 
12 Mar 2010

M Zimbone, G Litrico, C Chibbaro, R Reitano

Biblio References: 
Volume: 81 Issue: 4 Pages: 045602
Physica Scripta