Solar Energy Organic-hybrid electronics Laboratory

We incorporated triphenylsulfonium triflate (TPST), a sulfonium-based additive consisting of polar triflate and bulky hydrophobic phenyl rings, to the PbI2 precursor solution for preparation of less-defect perovskite film via two-step fabrication. TPST induced localized alterations in the array of the PbI2 structure due to its large size, thereby forming a more discontinuous and coarser surface with a greater number of pinholes and subsequently facilitating more efficient organic–inorganic reactions. As a result, we achieved the production of thick perovskite films with enlarged granules and decreased PbI2 residuals in the two-step fabrication process. Furthermore, TPST facilitated the passivation of bulk film defects by increasing the binding energy with the defects. Consequently, the ITO/SnO2 np-based device and the FTO/CBD SnO2-based device obtained the best PCEs of 23.88% and 24.30%, respectively. Furthermore, the moisture stability of the perovskite was improved by the hydrophobic character of the TPST additive.

Despite the notable advancements in perovskite photovoltaic technology, the performance and stability of flexible perovskite solar modules (f-PSMs) fall behind commercial standards. Conventional colloidal SnO2 electron transport layer (ETL) creates an efficiency-stability trade-off in flexible perovskite solar cells (f-PSCs). The developed multi-layer (ML) ETL resolves this trade-off by improving the surface coverage without scarifying the charge-transporting property and enables efficiencies of 22.9% on f-PSCs (0.1 cm2) and 16.4% on f-PSMs (900 cm2). In addition, the ML ETL improves the operational stability of f-PSM.

For the last decade, perovskite solar cells have been in rapid growth, highlighted as a representative next-generation solar cell. Although SnO2 is suitable as the electron-transporting material of perovskite solar cells, there also have been some obstacles in the formation of uniform and thin layers of SnO2 on the uneven FTO substrate. In this work, we investigated polymer-assisted fabrication methods to achieve conformal coating of SnO2 nanoparticles on rough FTO substrate, finally leading to improved performance of perovskite solar cells due to enhanced coverage and optimized electron-transporting property. As a result, we fabricated an efficient perovskite solar cells with a power conversion efficiency of 24% by employing polymer-capped SnO2 nanoparticles as electron-transporting layer.