Process produces stable heat- and water-resistant perovskite materials for use in photovoltaic and light-emitting applications
UCF researchers have developed a simple, cost-effective method of fabricating perovskite-polymer composite materials with high photoluminescence quantum efficiency, exceptional moisture insensitivity and long-term stability. The new process resolves the instability issues that occur when organic-inorganic hybrid perovskite materials are exposed to external stresses (such as heat, water, light and electrical fields). Using the new method, manufacturers can now create and use highly stable perovskites to produce low cost, reliable, high-performance products. For example, the method can be used to create displays that withstand harsh environmental conditions—until now, no other means has been available.
The new method uses a swelling-deswelling microencapsulation process to create solution-processable organic-inorganic perovskites (OIPs). The swelling-deswelling encapsulation method involves three components: perovskite precursors, solvents, and polymer substrates. The substrates swell when brought into contact with the solvents and deswell when the solvents are removed.
The method starts with a perovskite precursor solution. The solution is processed directly onto a polymer matrix using a solvent combined with a procedure such as spin coating, dip coating or slot die coating. The solvent penetrates the polymer matrix and causes swelling, which allows the perovskite precursors to enter the polymer. Afterward, the solvent is removed from the polymer matrix, leaving the perovskite precursors in the matrix to react and form perovskite nanocrystals. The polymer subsequently deswells, forming a barrier layer around the perovskite nanocrystals to create a stable perovskite-polymer composite. Numerous types of perovskites, solvents and polymers may be used, as long as the polymers swell and deswell when solvents enter and exit them.
Low cost and simple to manufacture
Provides heat and water resistance to display applications (up to 180 C)
- Highly efficient LED down-converters or emitters for displays and solid-state lighting
- High efficiency active absorbers or passive luminescent concentrators for solar photovoltaics
- Lasers and chemical sensors
Non-linear optical/photoconductive devices