Role of localized donor states in transport and photoluminescence of InN revealed by hydrostatic pressure studies

摘要

Pressure-dependent transport and photoluminescence (PL) measurements were performed on InN. In the transport measurements on the sample with a low electron concentration (n(e) lower than about 10(18) cm(-3)) a Localized Donor State (LDS) was seen to cross the Fermi level at elevated pressure magnitude. It was accompanied by the transfer of electrons from the Conduction Band to the LDS and a significant increase in electron mobility. In a sample with a higher concentration of electrons no transport anomaly was observed. Application of pressure helps to confirm that the disputed photoluminescence mechanism in InN consists in band-to-band recombination. No evidence of the participation of this LDS in radiative recombination processes was found in the pressure-dependent PL measurements. On the contrary, the dependence of the PL intensity on excitation power suggested the involvement of the LDS in nonradiative recombination processes. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.