Researchers at the Tokyo Institute of Technology and Nihon University in Japan have explored a new approach using an exciton confinement effect to optimize highly efficient perovskite LEDs.

The structure of a large perovskite LED, where a layer of zinc oxide was deposited on the a-zinc silicate electron transport layer, providing greater brightness with better power efficiency. Credit: Tokyo Institute of Technology

To achieve an efficient electroluminescent device, the team required a high photoluminescence quantum yield emission layer, efficient electron hole injection and transport layers, and high light out-coupling efficiency. With each new advance in emission layer materials, new functional materials are required to realize a more efficient LED. To accomplish this goal, the authors of the study explored the performance of an amorphous zinc-silica-oxide system layered with perovskite crystals to improve the diode performance.

Scientists at Kyushu University in Japan have created micrometer-thick organic light-emitting diodes (OLEDs) by integrating thick layers of hybrid perovskite with thin organic layers. Such devices have the potential to enhance the viewing angles and affordability of high-performance TVs and various other displays.

A test organic light-emitting diode (OLED) incorporating thick layers of hybrid perovskite emits green light. (Image credit: William J. Potscavage Jr., Kyushu University)

OLEDs use layers of organic molecules to efficiently change electricity into light. While these molecules are excellent emitters, they are usually poor conductors of electricity. This is why researchers strive to use extremely thin layers (around 100 nm) to allow electricity to easily reach where emission takes place in the center of the devices.