On the photoluminescence and energy transfer of SrGa12O19:Cr3+,Nd3+ microscale NIR phosphors

This work concerns Cr3+ and Nd3+ co-activated SrGa12O19 phosphors, which were synthesized by high temperature solid-state method using oxides and carbonates as starting materials. Luminescent samples according to SrGa12O19:Cr3+,Nd3+ comprise Cr3+ for the absorption of UV and visible radiation (250–700 nm) prior to energy transfer to Nd3+. The result of the energy transfer between Cr3+ and Nd3+ is the observation of line emission originating from Nd3+ in the near infrared range. The energy transfer from Cr3+ to Nd3+ is discussed via the variations of the lifetime values of Cr3+, and the thermal quenching behavior is also described. The strong absorption of Cr3+ in the visible range and the efficient energy transfer from Cr3+ to Nd3+ indicate that the herein presented material type can serve as a radiation converter to improve the efficiency of photovoltaic devices based on silicon cells.