Cathodoluminescent Measurements in GaP (Zn, O)

Cathodoluminescent measurements have been made on red emitting Zn–O-doped GaP. With a nonfocused beam, the minority carrier diffusion length Ln and the surface recombination velocity S have been obtained. For a particular illustrative sample, these values were found to be Ln=0.5±0.2 μm and S=5×105 cm/sec. The high generation rates achieved with a finely focused electron beam (∼0.5 μm) result in a near square-root dependence of emission on excitation. This dependence requires that the nonradiative centers as well as the radiative centers are saturated.