Study of a Stack of Perovskite/PEDOT: PSS for Solar Cells in Ambient Conditions

Over the recent years, we have witnessed significant progress in the development of organic-inorganic halide perovskite solar cells (PSCs), resulting in highly efficient solar technology. Poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) has been widely used as the hole transport material in optoelectronic devices. In our work, the structure elaborated was composed of FTO/ (PEDOT: PSS)/ perovskite/ C60/Al. We focused on the perovskite film preparation and our experiments revolved around two key aspects: The first involved optimizing the solution-processing parameters. After experimenting with various formulations and preparation methods of the perovskite precursor solution, our attention turned to the use of triple cations perovskites Cs(MaFa)PbBrI, described as more stable and less sensitive to processing conditions [1]. We also made adjustments to the spin-coating deposition and annealing parameters, including deposition speed (2000 rpm to 6000rpm), duration (15min to 30min), as well as annealing temperatures (60 to 120°C). Secondly, we replaced the conventional anti-solvent strategy with a vacuum-based method. This method involves placing the perovskite film within a vacuum container to boost rapid crystallization of the perovskite by removing most of the residual solvents. The thickness of PEDOT: PSS was controlled by deposition speed. The surface morphology was studied by scanning electron microscopy (SEM). The absorbance of our structure was measured by UV-Visible spectroscopy and contact angle measurements were used to investigate the hydrophobicity surface. We achieved positive results, leading to the development of stable perovskite films able to endure ambient air conditions for extended periods.