Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
DOI: https://doi.org/10.29363/nanoge.hopv.2022.288
Publication date: 20th April 2022
Since 2009, there has been research into the use of lead halide perovskites in solar cells (PSCs) [1]. Over the last decade the achievable power conversion efficiencies of PSCs have improved to compete with silicon solar cells. However, the traditional Antisolvent method for PSCs synthesis is not feasible for large scale production as it requires large amounts of organic solvents and high annealing temperatures. This poster is focused on an antisolvent free synthesis technique using Flash infrared annealing (FIRA). Flash Infrared annealing can control the crystal growth of the perovskite by altering the irradiation time [2]. FIRA has huge potential in the up-scaling of FAPbI3 solar cell synthesis as it is economically and environmentally favourable due to the short irradiation time (640 ms) and lack of organic solvent.
This poster reports the use of FIRA in the synthesis of FAPbI3 perovskite films and potential ways the power conversion efficiency (PCE) of the films can be improved. We analysed the FIRA process parameters and the use and effect of surface passivation and precursor composition. The FIRA annealing time was optimised to 640 ms allowing the complete evaporation of precursor solvent without causing decomposition of the film.
Surface roughness was the main factor affecting the performance of the FAPbI3 solar cells. Various methods to mitigate the issue were investigated, from the composition of the precursor to different kinds of post-treatments. Treating the perovskite films with formamidinium iodide and phenethylammonium iodide improved the measured PCEs. Coating the films with carbon (20nm) also improved the films efficiencies as created a good conductive layer that reduced thermal damage and loss of performance due to the perovskite roughness. The efficiency of the perovskite films were also improved by altering the precursor composition. Doping the precursor solution with TEMPO reduced the roughness of the perovskite surface by almost 20 nm and improved the overall stability of the synthesised films. The highest measured PCE was 17.92%, with a VOC of 1.06 V, a JSC of 22.77 mA/cm2 and an FF of 70.4%.
EPFL and supervisor Sandy Sanchez.