Tin halide perovskites are among the candidates for replacing lead-based ones for less toxicity and comparable optical properties. However, stability remains a challenge due to the easier oxidation of Sn²⁺ than Pb²⁺. Here, for the first time, we applied the ligand-assisted reprecipitation method to synthesize CH(NH₂)₂SnI₃ (FASnI₃) orthorhombic perovskite nanocrystals with an average diameter of 7.7 nm and a photoluminescence emission at 825 $\pm$ 2 nm (1.5 eV). The influence of synthesis parameters, including precursor solvent, precipitation media, temperature, and time on optical properties of nanocrystals, was studied. By incorporating SnF₂, the stability of the nanocrystals was improved, and the oxidation from FASnI₃ to FA₂SnI₆ was significantly delayed, which was quantitively demonstrated and confirmed by observing the characteristic diffraction peaks of the perovskite phase using x-ray diffraction at various exposure time to air. The addition of SnF₂ is optimized to be 6%. The FASnI₃ nanocrystals stayed stable for at least 265 days under N₂ storage at room temperature and relative humidity of 20%.

Power conversion efficiency (PCE) of single-junction perovskite solar cells (PSCs) has already soared from 3.8% to more than 26%. Their potential for application in tandem architecture with silicon and other established solar technologies has been deemed the future of low-cost solar technology. However, the commercialization of this technology is critically limited by instability under operational and environmental stress. The instability in the PSCs stems from both internal mechanisms including ion migration, defect formation, and electrode or charge transport layer (CTL)-induced degradation as well as external stressors such as moisture, oxygen, heat, and illumination. A complete understanding of both the internal and external stimuli-induced degradation and their mitigation strategies is essential for improving the device’s longevity. This review aims to provide a complete overview of the degradation mechanisms and steps taken to mitigate the degradation issues. The first half of the review discusses the degradation mechanism caused by internal degradation factors and provides strategies to mitigate them, while the second half focuses on the external stressors and the approaches developed by the perovskite community to overcome them. The commercialization of PSCs will depend on a holistic approach that simultaneously ensures both intrinsically as well as extrinsically stable devices.

Doping lithium into nickel oxide not only improves its electrical conductivity but also facilitates lithium-ion diffusion into the perovskite, enhancing the quality of the absorber and, consequently, the performance of the solar cell.

We report Sn-based Perovskite thin film solar cells with enhanced stability. For the perovskite FASnI3 thin film absorber is used with various additives such as SnF2 which exhibited long term stability against oxidization from Sn2+ to Sn4+ because of the thermodynamic stability of this compound. The PL measurement of the absorber film showed the PL maximum around 830 nm, which corresponded to an energy of 1.49 eV. A typical device structure was Glass/ITO/NiOx or PEDOT:PSS/ FASnI3/PCBM/BCP/Ag. The charge transport and stability of the cells were improved using additives and ultrathin buffer layers deposited using atomic layer deposition (ALD) techniques. We will present devices performance together with stability of the cells.