Measurement of the diffusion length and the lifetime of free excitons in gallium nitride using cathodoluminescence under different conditions of luminescence excitation

Using single-crystal n -GaN as an example, some possibilities of a procedure for quantitative cathodoluminescence of the direct-gap material are considered. This procedure is based on using the dependence of the cathodoluminescence intensity on the beam-electron energy at a constant level of electron-hole pair generation. Estimates of the diffusion length and the lifetime of free excitons and of the spectral dependence of the coefficient of recombination-radiation self-absorption are obtained using this procedure.