Europhys. Lett.
Volume 71, Number 6, September 2005
Page(s) 994 - 1000
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 10 August 2005
Europhys. Lett., 71 (6), pp. 994-1000 (2005)
DOI: 10.1209/epl/i2005-10170-7

A model for steady-state luminescence of localized-state ensemble

Q. Li, S. J. Xu, M. H. Xie and S. Y. Tong

Department of Physics and HKU-CAS Joint Laboratory on New Materials The University of Hong Kong - Pokfulam Road, Hong Kong, PRC

received 3 February 2005; accepted in final form 12 July 2005
published online 10 August 2005

A distribution function for localized carriers, $f(E,T)=\frac{1}{e^{(E-E_a)/k_BT}+\tau_{tr}/\tau_r}$, is obtained by solving a rate equation, in which electrical carriers' generation, thermal escape, recapture and radiative recombination are taken into account. Based on this distribution function, a model is developed for luminescence from localized-state ensemble with a Gaussian-type density of states. The model reproduces quantitatively all the anomalous temperature behaviors of localized-state luminescence. It reduces to the well-known band-tail and luminescence quenching models under certain approximations.

78.55.-m - Photoluminescence, properties and materials.
71.23.An - Theories and models; localized states.
78.60.-b - Other luminescence and radiative recombination.

© EDP Sciences 2005