Improving PSCs’ Short-circuit Current by Adding NaErF 4 :0.5%Tm@NaLuF 4 Up-conversion Nanoparticles Insertion Layer

I n this study, we synthesized a core-shell structure of up-conversion nanoparticles (UCNPs) and deposited it on the surface of fluorine-doped tin oxide (FTO). Subsequently, we assembled a series of perovskite solar cells with FTO/UCNPs/c-TiO 2 /mp-TiO 2 /MAPbI 3 /Spiro-OMeTAD/Au structures with an effective area of 0.04 cm 2 . To optimize the devices, we adjusted the concentration of UCNPs precursor. The optimized device showed a power conversion efficiency (PCE) of 16.73% and a short-circuit current density ( J sc ) of 26.94 mA/cm 2 at AM 1.5. These values are 9.20% and 10.47% higher than those of the best performing control device (15.32% for PCE and 24.12 mA/cm 2 for J sc ), respectively. Furthermore, we characterized the perovskite layer, charge transport layer, and perovskite solar cells using various analytical methods. The results showed that the addition of UCNPs not only improved the charge extraction and transfer, but also enhanced the stability of electron transport layer devices. In conclusion, our findings offer a process for optimizing perovskite cells using UCNPs and preliminarily analyzing their principles.