NREL scientists have developed a novel two-step process to prepare formamidinium lead iodide (FAPbI3) perovskite solar cells that—when compared to methylammonium lead iodide (MAPbI3) perovskite devices—have a 0.1-eV lower bandgap and an improved photocurrent density. This novel process involves preparing a MAPbI3 film through an existing deposition method (e.g., atomic layer deposition, chemical vapor deposition, or physical vapor deposition) and then heating this film under formamidinium gas to replace the existing methlyammonium with formamidinium following an aminium displacement reaction. In addition, this two-step process promises a general approach for producing formamidinium-based perovskites.
This technology is within the Film Chemistry and Film Efficiency categories of NREL’s perovskite portfolio. For further information regarding NREL's broader perovskite portfolio, please visit NREL's Perovskite Patent Portfolio website.
The Film Chemistry category consists of alternative film chemistries to the common methylammonium lead halide (CH3NH3PbI3) perovskite devices. These alternative film compositions have been shown to improve performance of perovskite films, including increased stability and efficiency, and to enable perovskite use in alternative mediums such as quantum dots.
The Film Efficiency category consists of film deposition methods, chemistry improvements, and device layer and architecture engineering that contribute to pushing commercial perovskite device efficiencies to 20% and beyond.
For more information, contact Bill Hadley at Bill.Hadley@nrel.gov
Applications and Industries
- 0.1-eV lower bandgap than MAPbI3 films
- Promises a general approach for FA-based perovskites