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 a method to fabricate a hermetically protected perovskite device with enhanced stability. This method consists of first coating an unencapsulated perovskite device with a metal oxide layer using a deposition process (e.g., physical vapor deposition, chemical vapor deposition, or atomic layer deposition) and then coating the metal-oxide layer with a sol-gel coating through either dip coating, spray coating, roll coating, or spin coating. The sol-gel coating used in this method is prepared through either the hydrolysis of a metal alkoxysilane in the presence of water and acid or through the co-polymerization of a metal alkoxysilane, an organically modified alkoxysilane, and a network forming organic molecule. In addition, the resulting device, after being tested in ambient conditions for 24 hours, had a great improvement in stability over an unprotected perovskite device, as demonstrated in Figure 1.
This technology is within the Film Stability 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 Stability category comprises technologies that improve perovskite devices’ resistance to environmental factors that degrade device performance over time. These technologies include methods of depositing perovskite films, encapsulant coatings, and novel film chemistries.
For more information, contact Bill Hadley at Bill.Hadley@nrel.gov.
Applications and Industries
- Enhances stability
- Hermetically protects perovskite devices
- Uses existing deposition and coating methods