Perovskite photovoltaics are a new class of light absorbers with exceptional and unparalleled progress in solar power performance. A perovskite is any material with a specific ABX3 crystal structure. In photovoltaic applications, the A cation can be either organic, inorganic, or hybrid in composition. The B component is typically a metal cation such as lead, and X is a halide such as iodine or bromine. Work on solar cells using perovskite materials has advanced rapidly as a result of the material’s excellent light absorption, charge-carrier mobilities, and lifetimes – resulting in high device efficiencies with low-cost, industry-scalable technology. While the potential for perovskite photovoltaic devices is high, commercialization will require overcoming other challenges relating to material stability, efficiency, and environmental compatibility.
NREL researchers have developed methods for the two-step solution growth and deposition of MAPbI3 perovskites. The novel two-step solution growth method involves pre-treating a PbI2 precursor film in an ether solvent, which leads to the rapid extraction of the solvent molecule from the PbI2 precursor film, and then dipping this pre-treated film into the MAI solution to produce MAPbI3 films. This method is applicable to other perovskite compositions and results in an increased PbI2-to-MAPbI3 conversion efficiency. In addition, the innovative deposition method applies a mix of a stoichiometric precursor with a non-stoichiometric MAPbI3 precursor and an excess amount of methylammonium halide to a substrate that is thermally treated to produce MaPbI3 perovskites with reduced hysteresis and that have a 2% to 3% increase in conversion efficiency when compared to a MAPbI3 film prepared with a standard stoichiometric precursor.
This technology is within the Film Deposition category of NREL’s perovskite portfolio. For further information regarding NREL's broader perovskite portfolio, please visit NREL's Perovskite Patent Portfolio website.
The Film Deposition category consists of novel methods for more rapid, less expensive, and more effective means of depositing perovskite films. These techniques have been published in multiple peer-reviewed journals and are prepared for scaling to commercial levels.
For more information, contact Bill Hadley at Bill.Hadley@nrel.gov
Applications and Industries
- Film Deposition
- Reduces PbI2-to-MAPbI3 conversion time
- Increases PbI2-to-MAPbI3 conversion efficiency
- Reduces hysteresis