Excitation-current-density and temperature dependences of deep UV cathodoluminescence in rocksalt-structured MgxZn1-xO films

Excitation-current-density and temperature-dependent cathodoluminescence (CL) spectra were measured for rocksalt-structured MgxZn1-xO films with x = 0.92–0.61. A deep UV luminescence (DUVL) band was predominantly observed in an energy range of 4.91–5.86 eV for all the films at 6–300 K. The analysis based on a rate equation model confirms that the DUVL band is attributed to the near-band-edge emission. Temperature-dependent CL spectra were quantified in terms of peak energy shifts and full width at half maximum values. Relatively high equivalent internal quantum efficiencies of 2.5%–11% were obtained for the RS-MgxZn1-xO films.