Synthesis and characterization of NaYF₄:Pr³⁺@NaYF₄:Eu³⁺ core@shell nanoparticles as down-conversion material for organic solar cells application

Here, a transparent luminescent down-conversion material (DCM) of NaYF₄:Pr³⁺@NaYF₄:Eu³⁺ core@shell nanoparticles has been used for OSCs application. The core@shell nanoparticles were prepared via a chemical sol–gel process. In OSCs, the prepared DCM is coated at backside of indium-doped tin oxide glass substrate, and the final device is called optimized device; whereas, the uncoated device is defined as control device. The power conversion efficiency of optimized device improved from 7.95 to 8.45%, as a result of the DCM re-emitting ultraviolet light in the visible range. Most importantly, the control device had inadequate stability under UV-B light, and within 90 min, efficiency has decreased by 38%. However, optimized device shows significantly superior performance by maintaining 84% of its initial PCE even after 90 min. It has been suggested that the NaYF₄:Pr³⁺@NaYF₄:Eu³⁺ DCM minimizes the ultraviolet deterioration while also improving the PCE of OSCs. Graphical abstract: (Figure presented.).