Enhancing the Efficiency of Tin-Lead Mixed Perovskite Solar Cells through Antioxidant Strategies

Addressing the Challenge of Tin Oxidation in Perovskite Solar Cells

In the quest for more efficient renewable energy sources, scientists have been drawn to the potential of perovskite solar cells. However, a significant challenge lies in the oxidation of tin in the tin-lead mixed perovskite materials used in these cells. Tin oxidation reduces the efficiency of these solar cells, prompting researchers to find ways to mitigate this process.

Recent studies have introduced the concept of using an electron withdrawing chloromethyl phosphonic acid ligand to suppress tin oxidation. This approach improves the redox potential of the tin adduct and significantly increases the ionization potential of the perovskite structure. As a result, researchers have achieved a record certified efficiency of 26.96% for all-perovskite tandem solar cells, as reported in a study published in the prestigious journal Nature (source).

Boosting Efficiency and Stability with a Multicomponent Approach

Another promising strategy to combat the challenges of mixed tin-lead perovskites is through a multicomponent approach. This strategy involves the development of methylammonium-free tin-lead perovskite solar cells, which have shown improved efficiency and stability. With this strategy, researchers have reported an efficiency of more than 22%, as detailed in the American Chemical Society's Energy Letters (source).

Utilizing Natural Antioxidants and Molecular Additives

Researchers have also explored the use of natural antioxidants and cyclic molecular additives to improve the performance of Sn-based perovskite films. For instance, ascorbic acid (VitC) has been found to inhibit the oxidation problem, while the addition of 18-Crown-6 further minimizes nonradiative recombination pathways. This approach has led to a significant improvement in the performance of 2D red Sn-based PeLEDs, as reported in Small (source).

Exploring the Potential of Natural Antioxidation and Microwave Irradiation

Beyond synthetic antioxidants, researchers have found potential in natural antioxidation strategies. For instance, vanillin, a natural antioxidant, has been used to inhibit the oxidation of Sn2+ or reduce Sn4+ back to Sn2+ in tin-based perovskite solar cells. Paired with short microwave irradiation, this technique has significantly improved the efficiency and stability of these solar cells. With 7.5% vanillin doping, an efficiency of 13.18% has been achieved, as reported in Advanced Functional Materials (source).

Overall, these studies highlight the critical role of electron-withdrawing ligands and antioxidants in modulating the energy levels and redox potentials of tin adducts. These findings provide valuable insights into the antioxidant properties of ligands and potential strategies for enhancing antioxidant capabilities to further boost the efficiency of perovskite solar cells.