Exploring solar alternatives
In the laboratory of William Tisdale, an assistant professor of chemical engineering, Sarah Arveson investigated thin films made of methyl ammonium lead bromide.Arveson tried out various methods for making thin films, varying the thickness and temperature, comparing spin coating to drop casting, and working in a glove box filled with nitrogen.
The solvent evaporates more quickly when spin coating at 1,500 rotations per minute, resulting in thin, uniform films.She also saw a mix of cubic and tetragonal phases in the scanning electron microscope images of the perovskite films, which at room temperature and pressure form cubic crystals.There is more stretching in one direction in the tetragonal phase.Additionally, Arveson experimented with iodine-doped hybrid films.
She elaborates, “There will be two or one iodine instead of three bromine molecules.”The iodine may alter the crystal’s optical or structural properties.The potential for high-efficiency solar cells is demonstrated by the perovskite crystal structure of the methyl ammonium lead bromide thin films.Because they are hybrid molecules that are both organic and inorganic, the organic part gives you malleability while the inorganic part gives you very high charge carrier mobility.Arveson explains that it is extremely pliable and supple.
