Researchers create efficient LEDs from mixed-dimensional perovskites on a fluoride interface

Researchers at The University of Cambridge and Zhejiang University recently created highly efficient LEDs by depositing mixed-dimensional perovskites on a thin lithium fluoride interface. The fabrication method they used reportedly resulted in LEDs with impressive external quantum efficiencies, while also enabling the deposition of perovskites on a material that they are typically incompatible with.

Efficient light-emitting diodes from mixed-dimensional perovskites on a fluoride interface imageImage from Nature Electronics

The researchers have been conducting research into perovskite-based LEDs for a few years now. Back in 2018, they created a near-infrared LED using perovskite-polymer heterostructures that achieved external quantum efficiencies of over 20% and internal quantum efficiencies of almost 100%.

New electron transport layer material could boost the stability of perovskite LEDs

A team of scientists from the NUST MISIS Laboratory of Advanced Solar Energy has proposed a new approach that uses the two-dimensional inorganic material zirconium trisulfide as the electron transport layer of a perovskite LED. In the future, this may allow the mass production of a new type of light-emitting diodes, as well as solving the problem of LED displays degradation, for example, in smartphones and TVs.

New ETL material could push forawrd perovskite LEDs image

The screens of many modern smartphones and TVs "suffer" from pixel burnout. Due to the presence of an organic component in OLED-type matrices (and their derivatives), pixels begin to degrade when the same icons on the screen are lit for a long time. So far, manufacturers advise users to periodically change the screen interface, rearrange the icons in places and regularly update the screen saver. In fact, the problem could be solved by minimizing the use of organic components in the screen matrix. Perovskite diodes are proposed as a way to make a revolution in designing screens.

Kyushu researchers use perovskites to create micrometer-thick OLEDs

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 imageA 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.

CSoT demonstrates a 6.6" 384x300 OLED display that uses perovskite quantum dots for color conversion

China-based display maker China Star (CSoT, a subsidiary of TCL) demonstrated a 6.6-inch 384x300 OLED display that uses perovskite quantum dots as a color conversion film.

CSoT is using blue OLED emitter materials, and a perovskite layer to up-convert the color to green (this is a monochrome prototype - evidently a very early prototype). CSoT brands its perovskite-OLEDs as PE-OLED and we believe this is the first time a perovskite-enhanced display has been publicly demonstrated.