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 NaYF 4 :Yb 3+ , Er 3+ nanoparticles (NPs) were successfully prepared by one-step hydrothermal route and incorporated into Al 2 O 3 as the scaffold layer for the air-processed carbon-based mesoscopic perovskite solar cells (MPSCs). FESEM shows that the size of NaYF 4 :Yb 3+ , Er 3+ nanoparticles is about 100 nm and there is no obvious agglomeration. The UV–vis–NIR absorption spectrum of the mixed scaffold layer demonstrates a distinct infrared light response. The infrared photoelectric efficiency and EQE tests were used to verify that NaYF 4 :Yb 3+ , Er 3+ 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% NaYF 4 :Yb 3+ , Er 3+ nanoparticles into the Al 2 O 3 scaffold layer, which shows a 20.6% increase 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.