The mystery of perovskites
The question we all might have though is: What are perovskites? When it comes to solar cells, most of us are aware that the highest energy market share is still owned by crystalline silicon-based solar cells. However, in the past years perovskite-based materials and their utilization in solar cells that exhibit rapid efficiency increase have been intriguing researchers.
The type of perovskites used in solar cell devices are commonly based on a mixed-halide structure. A halide is composed of two components: a halogen atom and an element or radical that is less electronegative. The Perovskite general formula can be written as ABX3, where A and B are cations and X is an anion. Most commonly used compounds are: methylammonium (CH3NH3)+ as compound A, lead (Pb+2) or tin (Sn+2) as B and chlorine (Cl−), bromine (Br−) or iodine (I−) as X. Although these materials are not yet long-term stable which is a crucial requirement for solar cell applications, they are easily prepared – making the perovskites very attractive materials for solar cell production. The main issue, however, is the fact that the perovskite-based solar cells are mainly fabricated with lead (Pb) which is toxic. Núria’s main interest and hard work are directed towards replacing Pb by tin making the heavy-metal dispensable from the perovskites.