One of the materials being investigated for use in making new types of solar cells is perovskite. The are several drawbacks to the material that researchers are working to overcome, and one of those drawbacks is reliability. A study conducted at Brown University has brought the perovskite solar cell one step closer to commercial use after the team found a way to strengthen one of the main weak points in this type of cell.
The team demonstrated a new “molecular glue” able to keep a key interface inside the cells from degrading. The treatment dramatically increases the stability and reliability of the cells over time. The treatment also improves the efficiency of converting sunlight into electricity inside the panels.
Perovskites are a class of materials with a unique crystalline atomic structure. Over a decade ago, scientists found that perovskites were very good at absorbing light, kicking off research into using the material in solar cells. The efficiency of perovskite solar cells has increased significantly and now rivals that of traditional silicon cells. Perovskite cells are highly desired because perovskite light absorbers can be made at near room temperature compared to silicon that requires temperatures of nearly 2700 degrees Fahrenheit.
Perovskite films are also 400 times thinner than silicon wafers meaning less material is required in their construction. Perovskite cells could potentially be made at a fraction of the cost of silicon cells. One key drawback for perovskite solar cells so far has been their stability and reliability.
Perovskite cells are made using five or more distinct layers, and the weakest of those layers is the one between the perovskite film used to absorb light and the electron transport layer that keeps current flowing through the cell. The new molecular glue strengthens that layer and has the potential to improve the solar cell significantly. The team used a formulation with compounds known as self-assembled monolayers using a silicon atom on one side and an iodine atom on the other.