Exciton localization in inhomogeneously broadened ZnO/MgxZn1−xO quantum wells
نویسنده
چکیده
Exciton localization in ZnO /MgxZn1−xO quantum wells QWs has been investigated systematically with various ZnO well widths for the fixed Mg0.23Zn0.77O barrier height. A strong exciton confinement is observed with an implicit dependence on the built-in electric field which is calculated to be 0.37 MV/cm. The exciton-phonon coupling strength varied significantly depending upon the degrees of exciton localization with the activation energy of 18–29 meV. The relaxation mechanism in ZnO /Mg0.23Zn0.77O QWs starts to dominate when the exciton localization energy is above the thermal energy, kBT. The band characteristics and strong exciton localization in ZnO /Mg0.23Zn0.77O QWs are attributed to the potential fluctuations associated with the inhomogeneous broadening, represented by the schematics. © 2010 American Institute of Physics. doi:10.1063/1.3452379
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تاریخ انتشار 2010