Efficient transparent quantum-dot light-emitting diodes with an inverted architecture

With the development of transparent electronics, there have been an increasing interest on variety of transparent and translucent optoelectronic devices in the visible range. Especially for transparent conducting films and transparent light-emitting diodes (LEDs), significant advancements have been made in the past two decades [1,2]. Due to the potential applications of transparent optoelectronic films and devices in the consumer electronics, new energy and automotive industries, this area has been attracting enormous attentions from both of academics and industries. Transparent quantum dots light-emitting diodes (Tr-QLEDs) have become the potential candidate for the next-generation transparent displays, augmented reality (AR), Transparent quantum-dot light-emitting diodes (Tr-QLEDs) with an inverted architecture has been developed. The inverted Tr-QLEDs are designed for integrating with thin-film transistors (TFTs) circuit easily. The 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HAT-CN) is employed as a hole injection layer (HIL) as well as a buffer layer in the inverted Tr-QLEDs. An optimized HAT-CN as dual-functional modified layer facilitates charge injection balance and meanwhile reduces the plasma damage caused by sputtering process. High performance device with a peak current efficiency (CE) and maximum external quantum efficiency (EQE) of 14.7 cd/A and 11.3% was obtained, wherein the EQE is the highest record for Tr-QLEDs. The transmittance of the Tr-QLEDs at 550 nm reached up to 78%. These Tr-QLEDs possess potential for the next-generation transparent displays applications.