Feasibility of Emission-Enhanced CsPbCl₃Quantum Dots Co-Doped with Mn²⁺and Er³⁺as Luminescent Downshifting Layers in Crystalline Silicon Solar Modules

In order to enhance the photoelectric conversion efficiencies of crystalline silicon (c-Si) solar cells, CsPbCl₃quantum dots (QDs) codoped with Mn²⁺and Er³⁺(CsPbCl₃:Mn²⁺, Er³⁺QDs) were mixed with ethylene-(vinyl acetate) (EVA) to form a film which was used as a luminescent down-shifting (LDS) layer. The LDS layer effectively improved the low utilization of near-ultraviolet light of c-Si solar cells. These CsPbCl₃:Mn²⁺,Er³⁺QDs were synthesized via a conventional high-Temperature injection method. Mn²⁺is the luminescence center, and the incorporation of Er³⁺greatly enhances the luminescence intensity of Mn²⁺. The absolute photoluminescence quantum yield of the QDs dispersed in toluene reached 79.5% when the QDs were synthesized under the optimum conditions, that is, an injection temperature of 180 °C and Pb:Mn:Er preparation molar ratios of 6:4:4. The EVA film embedded with QDs at the optimum concentration (0.9 wt %) was used as an LDS layer for c-Si solar module. The short-circuit current (I_SC) and the photoelectric conversion efficiency (η) were increased by 3.42% and 4.02%, respectively, owing to the LDS layer. Moreover, a luminescent solar concentrator (LSC) which was another application of luminescent materials was also demonstrated. For LSC, the relative changes in I_SCand η by using the QDs-dispersed EVA film were +14.9% and +18.0%, respectively. These results indicate a feasible application of luminescent downshifting films in solar modules.