title: Dynamics of nonequilibrium carrier decay in AlGaN epitaxial layers with high aluminum content.
abstract: Carrier dynamics in high-Al-content AlGaN epilayers with different dislocation densities from 5 × 10(8) cm(-2) to 5 × 10(9) cm(-2) is studied by comparing the photoluminescence decay with the decay of carrier density. The carrier density decay was investigated using the light-induced transient grating technique. This comparison shows that the luminescence at the nonequilibrium carrier densities expected in operating light-emitting diodes depends on the recombination of free carriers and the localized exciton-like electron-hole pairs and localization-delocalization processes. In addition, a fraction of the nonequilibrium carriers is captured by the deep capture centers with extremely long lifetimes. These carriers have an insignificant contribution to the band-to-band radiative recombination. This capture is an important factor in decreasing the emission efficiency.
authors.forename: Tanuj
authors.initials: T
authors.lastname: Saxena
authors.forename: Michael
authors.initials: M
authors.lastname: Shur
authors.forename: Saulius
authors.initials: S
authors.lastname: Nargelas
authors.forename: Žydrūnas
authors.initials: Ž
authors.lastname: Podlipskas
authors.forename: Ramūnas
authors.initials: R
authors.lastname: Aleksiejūnas
authors.forename: Gintautas
authors.initials: G
authors.lastname: Tamulaitis
authors.forename: Max
authors.initials: M
authors.lastname: Shatalov
authors.forename: Jinwei
authors.initials: J
authors.lastname: Yang
authors.forename: Remis
authors.initials: R
authors.lastname: Gaska