Air-processed hole-conductor-free and printable infrared light responded carbon-based perovskite solar cells using up-conversion NaYF4:Yb3+, Er3+nanoparticles

The introduction of up-conversion materials converting near infrared light into useable visible light has been proven to be a promising strategy for improving the performance of perovskite solar cells. In this work, the up -conversion material of NaYF4:Yb3+, Er3+ nanoparticles (NPs) were successfully prepared by one-step hydro -thermal route and incorporated into Al2O3 as the scaffold layer for the air-processed carbon-based mesoscopic perovskite solar cells (MPSCs). FESEM shows that the size of NaYF4:Yb3+, Er3+ nanoparticles is about 100 nm and there is no obvious agglomeration. The UV-vis-NIR absorption spectrum of the mixed scaffold layer dem-onstrates a distinct infrared light response. The infrared photoelectric efficiency and EQE tests were used to verify that NaYF4:Yb3+, Er3+ nanoparticles improved the photo response of the device in the infrared region, thereby improved the photoelectric performance of the MPSCs. An optimal efficiency of 13.04% was obtained by incorporating 25 wt% NaYF4:Yb3+, Er3+ nanoparticles into the Al2O3 scaffold layer, which shows a 20.6% in-crease in conversion efficiency when compared with the device without using the up-conversion material (10.81%). The optimized carbon-based MPSCs also show an infrared responded PCE value of 0.11% under infrared irradiation from 800 to 1100 nm. This paper shows that the up-conversion material expands the light response of solar cells to the infrared region and provides an effective method for the preparation of high -efficiency perovskite solar cells.