Hot carrier luminescence during porous etching of GaP under high electric field conditions

Electroluminescence is observed during porous etching of n-type GaP single crystals at strongly positive potential. The emission spectra, which include a supra-bandgap contribution, are markedly different from the spectra observed under optical excitation or minority carrier injection. The current density and electroluminescence intensity show a strong potential dependence and a similar hysteresis. The spectral characteristics of the luminescence suggest that both thermalised and hot charge carriers, generated by impact ionisation, are involved in light emission.