Eu2+-Nd3+ co-doped glasses for solar spectrum modification via NUV/visible to NIR downconversion

Abstract The challenge of modifying the solar spectrum intensifies efforts in the pursuit of enhanced materials and optical systems. In this work, we present novel and efficient near infrared-emitting Eu2+ and Nd3+ co-doped sodium calcium silicate glasses. Optical absorption, excitation spectra, emission decay time, were measured and discussed as a function of Nd2O3 content. Laser power-dependent emission intensity was used to evaluate the transfer mechanism, and an energy level diagram was proposed. For the sample doped with optimized neodymium content, energy transfer efficiency reached 70%. For co-doped samples, the excitation spectrum was broadly intense and perfectly overlapped with the solar spectrum in the NUV region. Therefore, NUV/Visible can be efficiently converted into NIR, precisely where the C-Si response is maximal, through the Eu2+→Nd3+ pathway. This work’s outcomes made the focused materials worthy for solar cell applications, optimizing energy conversion lost by thermalization, into useful energy.