Perovskite films to enable color-enhanced displays

National University of Singapore researchers have developed a perovskite-based color-enhancement film that may enable richer and more natural colors to next-generation flat-panel electronic displays. The research team is currently working with display companies to commercialize the perovskite color-enhancement film, and hopes to see the technology in consumer electronic products within the next two to three years.

Current commercial display technologies such as OLEDs (organic light-emitting diodes) and QLED (quantum dot light-emitting diodes) can only produce slightly more than 50% of the colors visible to the human eye. This limits the color reproduction that these displays can achieve. A research team from the Department of Chemistry and the Solar Energy Research Institute of Singapore (SERIS) at NUS has developed a color-enhancement film that could allow future display technologies to produce more than 75% of all visible colors. This technology is enabled by using perovskites, which can be tuned by changing its chemical composition to emit light strongly and efficiently in a variety of colors. To make the enhancement films, the research team mixed manometer-sized crystals of the perovskite material with a liquid monomer (precursor of plastics), and triggered a polymerization reaction by illuminating the mixture with white light.

This process allowed the team to fabricate a strongly luminescent perovskite-polymer composite film that reportedly possesses a threefold enhancement in luminescence efficiency compared to a conventional perovskite nanocrystal film. The improved luminescence performance is a result of the increased spatial separation between the perovskite nanocrystals in the polymer composite material, which prevents the channeling of energy between crystals to the defective and non-emissive ones. This innovation allows perovskite materials to emit light more efficiently and consume less energy when deployed in a display product.

Dr. WONG Ying Chieh, a member of the research team, said, "An added advantage is that perovskites are easy to synthesize, potentially facilitating their scale-up and reducing the production cost of displays. The time taken for perovskite precursor chemicals to react and form nanocrystals is typically on the order of 10 seconds."

"Perovskite materials can be coated and processed in a solution form which is similar to paints, and can potentially be used in large-area displays. Although our materials are useful in enhancing the performance of televisions and mobile devices, my vision is to put them into wall-sized displays in our living or work spaces to create realistic virtual environments with rich and natural colors," added Prof Tan.