Electronic behavior of rare-earth dopants in AlN: A density-functional study
2005; American Physical Society; Volume: 72; Issue: 7 Linguagem: Inglês
10.1103/physrevb.72.073205
ISSN1550-235X
AutoresS. Petit, R. Jones, M. J. Shaw, P. R. Briddon, B. Hourahine, Thomas Frauenheim,
Tópico(s)ZnO doping and properties
ResumoLocal density functional calculations are carried out on Er, Eu, and Tm rare-earth (RE) dopants in hexagonal AlN. We find that the isolated impurities prefer to substitute for Al and, in contrast with isolated RE dopants in GaAs and GaN, ${\mathrm{RE}}_{\mathrm{Al}}$ defects are electrically active and introduce deep donor levels around ${E}_{v}+0.5\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. RE complexes with oxygen and vacancies are discussed; some of these have deep levels in the upper third of the gap and could account for a threshold excitation energy around $4\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ observed for intra-$f$ transitions at 465 and $478\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ in AlN:Tm.
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