Photoluminescence in Er-implanted AlGaN/GaN superlattices and GaN epilayers

摘要

Photoluminescence (PL), structural and electrophysical properties of Al0.26Ga0.74N/GaN superlattices grown by metal-organic chemical vapor deposition, implanted by erbium (Er) ions with 1 MeV energy and 1 X 10(15)cm(-2) dose as well as annealed at 700-1100degreesC for 4 min in argon have been investigated. A comparison of the properties of the superlattices with that of the GaN epilayers grown, implanted and annealed at the same conditions is also given. The Er-related peak with a maximum at lambdasimilar to1.54 mum dominated and the defect-related emission band at lambdasimilar to1-1.4 mum was observed in the PL spectra of both types of samples. When the measurement temperature was increased from 80 to 300K, practically the same temperature quenching of the Er-related intensity was observed in the superlattices and GaN epilayers implanted and annealed at the same conditions. The Er-related intensity at 300 K increased monotonically as the annealing temperature was raised from 700 to 1000degreesC, but the intensity in the superlattices was higher by several times than that in the epilayers. A decrease of the Er-related PL intensity in the superlattice after annealing at 1100degreesC is associated with the formation of non-radiative recombination centers. (C) 2003 Elsevier B.V. All rights reserved. [References: 9]