Visible to infrared down conversion of Er3+ doped tellurite glass for luminescent solar converters

•The effect of erbium adding on thermal and structural properties of Er3+ doped tellurite glass was investigated.•Using optical absorption data and Judd-Ofelt theory, several spectroscopic properties were examined with respect to the Er2O3 content and compared to other glass systems.•Using an excitation wavelength of 488 nm, a detailed study on the down-conversion mechanism in the Er3+ system was presented.•A high quantum efficiency (91%), large emission cross section (9.1 10−21 cm2), effective bandwidth exceeding 100 nm attributed to the emission at 1.53 µm were obtained and the responsible mechanisms was suggested to explain this enhancement.