Comparative study of Er-implanted Si, ZnAs2 and CuInSe2

The indirect- (Si) and direct- (ZnAs2, CuInSe2) band-gap semiconductors, with Eg of about 1 eV, ion-implanted with 350 keV Er, were studied using photoluminescence (PL). The PL spectra measured from each material revealed an emission line at about 1.54 μm associated with the internal 4f11 transition (4I13/2→4I15/2) of Er. In the direct-gap semiconductors CuInSe2 and ZnAs2, the Er-related emission was observed straight after the implantation and prior to any annealing whereas in Si such emission is only detectable after thermal annealing at 600 °C. The PL temperature dependencies from 4.2 to 300 K are discussed for all the materials.