Low threshold for optical damage in AlGaN epilayers and heterostructures.

Autor: Saxena, Tanuj, Tamulaitis, Gintautas, Shatalov, Max, Yang, Jinwei, Gaska, Remis, Shur, Michael S.
Předmět:
Zdroj: Journal of Applied Physics; Nov2013, Vol. 114 Issue 20, p203103, 5p, 4 Graphs
Abstrakt: Laser pulses with duration much shorter than the effective carrier lifetime cause permanent photoluminescence (PL) quenching and enhancement of PL decay rate in bare-faceted and capped AlGaN epilayers and multiple quantum wells at pulse energies about an order of magnitude lower than those causing the surface to melt and degrade. In contrast, GaN epilayers exhibit no photomodification in the same excitation intensity range. PL spectra and decay kinetics show that lattice heating is not responsible for the observed changes in AlGaN, which result from the formation of nonradiative recombination centers via recombination-enhanced defect reactions occurring at high nonequilibrium carrier densities. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index