An approach to ZnTe:O intermediate-band photovoltaic materials

ZnTe epitaxial layers with different crystalline quality were grown by molecular beam epitaxy. ZnTe:O was achieved by oxygen incorporation in ZnTe films using ion implantation. The proper concentrations of O ions attributed to the formation of the intermediate band which was approximately 1.88 eV above the valence band maximum. Pulsed laser melting was then carried out on the samples. ZnTe with high crystalline quality and appropriate concentrations of oxygen ions led to the improvements of absorption efficiency of the intermediate band. The results suggest that factors such as the crystalline quality and the dose of O concentration are important to achieve better ZnTe:O intermediate-band photovoltaic materials. The way we utilize to fabricate ZnTe:O intermediate band solar cell materials is applicable, and the position and intensity of O states could be well controlled.