The most promising new solar cell technology is based on halide perovskites. The heart of the halide perovskite solar cell is a thin film of light-absorbing material that has the perovskite crystal structure.
The general chemical formula is ABX₃, where A is an alkali metal or amine, B is Sn or Pb, and X is halide. CH₃NH₃PbI₃(methylammonium lead iodide, MAPI) is the most studied absorber material in halide perovskite solar cells. In the solar cell, the halide perovskite layer is sandwiched between thin semiconducting layers and electrical contacts.
Despite its great promise, the halide perovskite technology has two major issues that currently limit its development. The issues are instability of the halide perovskites and the lack of scalable preparation methods.
The aim of this new Academy of Finland project is to find solutions to these issues by developing new preparation methods for the thin film materials needed in halide perovskite solar cells. Our approach relies on atomic layer deposition (ALD), a unique method that enables the deposition of uniform films over large areas. Even though a large number of ALD precursors and processes exist for various materials, no suitable processes are currently available for most of the materials needed in this work.