Tin-Based Perovskite Solar Cell Technologies

Tin-based perovskites have emerged as the leading candidate for lead-free photovoltaic absorbers, combining an optimal bandgap near 1.3 eV with strong optical absorption and high charge-carrier mobilities. By replacing toxic lead with tin, these materials promise environmentally benign solar modules while retaining the low-cost solution processing characteristic of halide perovskites. However, they face unique challenges: facile oxidation of Sn(II) to Sn(IV) generates deep trap states, rapid crystallisation leads to inhomogeneous films, and moisture or oxygen ingress accelerates degradation. Recent progress has focused on composition and additive engineering, interface and layer design, and novel device architectures to suppress Sn(II) oxidation, passivate defects and enhance operational stability, thereby driving power conversion efficiencies above 12 % in laboratory cells.

Research from Nature Portfolio

Recent studies have elucidated the fundamental degradation pathways of mixed-cation tin perovskite films, revealing a cyclic mechanism in which SnI₄ by-products evolve into iodine under moisture and oxygen, further oxidising Sn(II). Tailoring the choice of hole transport layer has been shown to disrupt this cycle and improve film resilience. Parallel work introduced in situ generation of tin(0) nanoparticles within precursor solutions, effectively scavenging Sn(IV) impurities to yield perovskite layers with prolonged photoluminescence lifetimes and enhanced open-circuit voltages. Additionally, the design of an amorphous-polycrystalline absorber architecture—combining a tin halide amorphous interlayer with cesium-formamidinium tin iodide crystals—has delivered certified efficiencies above 10 % and maintained over 95 % of initial performance after 1,000 hours under continuous illumination.

Tin-Based Perovskite Solar Cell Technologies publication trend

The graph below shows the total number of articles in tin-based perovskite solar cell technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Perovskite: A crystalline structure of formula ABX₃, where A and B are cations and X is an anion, renowned for optoelectronic properties.

Power conversion efficiency (PCE): The ratio of electrical power output to incident solar power, expressed as a percentage.

Sn(II)/Sn(IV) oxidation states: Tin exists as divalent Sn(II) in perovskites; oxidation to tetravalent Sn(IV) introduces defect states that diminish performance.

Defect passivation: Strategies to neutralise or eliminate electronic traps at surfaces or grain boundaries, often via additives or interfacial layers.

Hole transport layer: A semiconductor layer that selectively extracts positive charge carriers (holes) from the perovskite absorber to an electrode.

References

1. Ligand Engineering in Tin-Based Perovskite Solar Cells. Nano-Micro Letters (2023).
2. Engineering Stable Lead‐Free Tin Halide Perovskite Solar Cells: Lessons from Materials Chemistry. Advanced Materials (2023).
3. Degradation mechanism of hybrid tin-based perovskite solar cells and the critical role of tin (IV) iodide. Nature Communications (2021).
4. Sn(IV)-free tin perovskite films realized by in situ Sn(0) nanoparticle treatment of the precursor solution. Nature Communications (2020).
5. Efficient and stable tin perovskite solar cells enabled by amorphous-polycrystalline structure. Nature Communications (2020).
6. Tin Halide Perovskites: From Fundamental Properties to Solar Cells. Advanced Materials (2021).
7. Ionic Liquid Stabilizing High‐Efficiency Tin Halide Perovskite Solar Cells. Advanced Energy Materials (2021).