Proceedings of Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP23)
DOI: https://doi.org/10.29363/nanoge.iperop.2023.048
Publication date: 21st November 2022
With the efficiencies of perovskite solar cells (PSCs) approaching 26%, the focus has turned to the fabrication of long-lasting scaled up devices. In this regard, slot-die coating has emerged as a front runner owing to its large area coating uniformity, high throughput capability, minimal material wastage, as well as compatibility with high volume production. To date, power conversion efficiency (PCE) of the state-of-the-art slot-die coated PSCs is over 20% for small-areas and over 19% for large-areas. As variation of crystallization kinetics and the presence of residual solvents can become more significant in large area coating, there is an urgent need for the development of approaches capable of addressing a wide variety of defects. We utilize a hydrophobic all-organic salt to modify the top surface of large area slot-die coated methylammonium (MA)-free halide perovskite layers. Endowed with anchoring groups capable of exhibiting secondary interactions with the perovskite surfaces, the organic salt acts as a molecular lock by effectively binding to both anion and cation vacancies, substantially enhancing the materials’ intrinsic stability against different stimuli. The treated PSCs demonstrate efficiency of 19.28 % for the corresponding mini-module (active area of 58.5 cm2). In addition to solution processing, deposition of perovskite absorber layers by thermal co-evaporation have gathered considerable interest for both single junction and multi-junction solar cells. The main advantages for thermal evaporation include conformal coatings, control of deposited layer thicknesses, and possibility of multi-layer processing. We have recently demonstrated highly efficient, large area, planar PSCs ranging from 0.16 cm2 to 20 cm2 with high efficiencies. This methodology is also compatible with depositing layers for quantum confinement that is crucial for optoelectronics applications.