Designing a novel Eu2+-doped hafnium-silicate phosphor for an energy-down-shift layer of CsPbI3 solar cells

Abstract

The excessive carbon discharge and low utilization efficiency of solar energy are still the biggest challenges in the world. A series of Eu²⁺ doped K₂HfSiO₅ phosphors were synthesized and applied in CsPbI₃ perovskite solar cells. Under the excitation of ultraviolet and near ultraviolet light in the range of 300–450 nm, K₂HfSiO₅:Eu²⁺ exhibits emission in the visible range of 450–650 nm. Due to their strong absorption in the ultraviolet region and high quantum efficiency, K₂HfSiO₅:Eu²⁺ phosphors could be used to fabricate an energy-down-shift layer for solar cells. When spin-coated with the layer, the value of the short-circuit current of the packaged CsPbI₃ solar cell increased, resulting in the enhancement of the power conversion efficiency by 2.19%. In addition, other basic properties of K₂HfSiO₅:Eu²⁺ phosphors such as photoluminescence, cathodoluminescence and stability have also been studied. All the results indicate that the energy-down-shift layer made using K₂HfSiO₅:Eu²⁺ phosphors has a positive effect on improving the performance of CsPbI₃ perovskite solar cells.