Comment on "random-walk model of energy transfer in cathodoluminescence"

The paper by Ozawa and Hersh suggests that the slope S of a log-log plot of cathodoluminescence vs activator concentration for host-excited phosphors is the "quantum efficiency" (QE) of the process. This comment shows that S can arise from the kinetics and need bear no simple relation to the QE which may well be unity. Further, the concentrations at which the plots for different phosphor-crystal sizes inflect cannot be calculated in the simple manner proposed by Ozawa and Hersh. A kinetic approach is described which reproduces the experimental data with reasonable parameters. © 1978 The American Physical Society.