Perovskite materials are defined by their unique ABX3 crystal structure, where "A" and "B" are cations and "X" is an anion.
The composition and stoichiometry of perovskite crystals can be altered to fit many different uses. They’re potential applications are only beginning to be explored, but some of the most popular uses of perovskites are in solar cell, LEDs, sensors and photodetectors.
In perovskite solar cells, the perovskite crystal typically consists of:
- A Cations - Primarily organic cations, such as methylammonium, formamidinium and occasionally small inorganic cations like caesium
- B Cations - Heavy metal cation, commonly lead (Pb) and sometimes tin (Sn)
- X Anions - Halogen ions, typically iodide, bromide, chloride, or fluoride
Perovskites often utilize multiple A, B and X components in one crystal to achieve ideal material properties (e.g. for bandgap tuning, stability improvements). This stoichiometry is very important and impact device performance significantly. For most perovskite solar cell, precursor salts are mixed into a solution, which can be deposited through various thin film coating methods. This is known as a perovskite precursor solution or perovskite ink.