Highly-efficient OLED with cesium fluoride electron injection layer

Abstract

The effective electron-injecting layer (EIL) is one of the important factors in organic light-emitting diodes (OLEDs) to achieve high performance devices. Herein, we have proposed the modification in cesium fluoride thickness and demonstrated that the performance of OLED is enhanced while varying the thickness of EIL. The cesium fluoride thickness may greatly influence the electron injection ability from the cathode to electron transport layer (ETL). The optimized green phosphorescent OLED consisting CBP:Ir(ppy)3 emissive layer reveals forward viewing power efficiency (PE) of 46.3 lmW−1, current efficiency (CE) of 51.7 cdA-1 and external quantum efficiency (EQE) of 14.2%, at 100 cdm−2, which has enhancement of PE, CE, and EQE of 38.6%, 44.8%, and 46.4%, respectively at 100 cdm−2. The thickness variation of cesium fluoride EIL resulted in very balanced electron injection which is also valid for other OLED devices. The employment of optimized EIL is a favourable approach to enhance the performance in OLEDs applications.