Photoluminescence study of Si doping cubic GaN grown on (001) GaAs substrates by molecular beam epitaxy

Citation
Zq. Li et al., Photoluminescence study of Si doping cubic GaN grown on (001) GaAs substrates by molecular beam epitaxy, J CRYST GR, 227, 2001, pp. 420-424
Citations number
17
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF CRYSTAL GROWTH
ISSN journal
00220248 → ACNP
Volume
227
Year of publication
2001
Pages
420 - 424
Database
ISI
SICI code
0022-0248(200107)227:<420:PSOSDC>2.0.ZU;2-Z
Abstract
The photoluminescence (PL) properties of Si-doped cubic GaN with different carrier concentrations were investigated at room temperature. The epilayers were grown on GaAs (0 0 1) by radio-frequency molecular beam epitaxy. It w as found that when the carrier concentration is increased fi om 5 x 10(15) to 2 x 10(18) cm(-3), the PL peak shifted towards low energy, from 3.246 to 3.227 eV, and the PL linewidth increased from 77.1 to 121 meV. The PL peak shift is explained by the bandgap narrowing effect due to the high doping concentration. The PL linewidth includes two parts: one is doping concentra tion independent, which is caused by the imperfection of samples and phonon scattering; the other is doping concentration dependent. We assign the sec ond part to the broadening by the microscopic fluctuation of the doping con centration. The experimental measurements are in good agreement with the mo del. (C) 2001 Published by Elsevier Science B.V.