Research Background
The external quantum efficiency of perovskite light-emitting diode (Peled) has exceeded 20%. However, visible perovskite LEDs are still affected by non radiative composite energy loss and carrier transport layer compatibility, so it is difficult to obtain high-performance devices reliably, which limits the further development of the field.
Highlights
This paper report efficient, green electroluminescence from mixed-dimensional perovskites deposited on a thin (~1 nm) lithium fluoride layer on an organic semiconductor hole-transport layer. The highly polar dielectric interface acts as an effective template for forming high-quality bromide perovskites on otherwise incompatible hydrophobic charge-transport layers. The control of crystallinity and dimensionality of the perovskite layer is achieved by using tetraphenylphosphonium chloride as an additive, leading to external photoluminescence quantum efficiencies of around 65%. With this approach, we obtain light-emitting diodes with external quantum efficiencies of up to 19.1% at high brightness (>1,500 cd m−2).
Summary
Recently, Dawei Di and Zhao Baodan, together with the team of academician Richard friend of Cambridge University, reported the high efficiency hybrid dimensional perovskite LED based on fluoride interface. Using ultra-thin (1 nm) lithium fluoride layer, the perovskite is crystallized on the incompatible high performance polymer semiconductor, which reduces the non radiative recombination loss of the device carrier transport layer interface. The external quantum efficiency of 19.1% was obtained at the brightness of > 1500 CD / m2, which created the efficiency record of green mixed dimension perovskite LED. This research provides a new idea for the preparation of high quality perovskite semiconductors and the integration of high performance devices.
Publishing Information
The results were published in Nature Electronics and selected as the cover paper【BaodanZhao, Yaxiao Lian, Dawei Di*, Richard H. Friend* et al, Efficient light-emitting diodes from mixed-dimensional perovskites on a fluorideinterface, Nature Electronics 3, 704–710 (2020) (cover article) DOI:10.1038/s41928-020-00487-4】
Full Paper Download Address:
https://www.nature.com/articles/s41928-020-00487-4
