Towards Spectrally Stable Blue Perovskite Light Emitting Diodes

Solution processable metal halide perovskites have emerged as new generation narrow band light emitters with applications in various optoelectronic devices, including light-emitting diodes (LEDs), lasers, and scintillators. Since the report of efficient room-temperature perovskite electroluminescence in 2014, remarkable progress has been achieved in the development and study of light-emitting perovskite materials and devices. While the device efficiencies of perovskite LEDs (PeLEDs) have significantly improved over a short period of time, their overall performance has not reached the levels of mature technologies yet, such as organic LEDs (OLEDs) and quantum dot LEDs (QDLEDs), to enable practical applications. Many issues and challenges, including low operational stability, lack of efficient blue PeLEDs, and toxicity of lead based perovskites, remain to be addressed. In this talk, I will present our recent efforts on the development of new materials and processing approaches for efficient and stable PeLEDs, in particular, blue PeLEDs. Various approaches of color tuning to obtain efficient blue emitting perovskite thin films will be discussed, for instance, surface passivated quasi-2D and nano-structured lead bromide perovskites. With blue emitting perovskite thin films, device integration and engineering have been carried out to achieve efficient LEDs, by combining them with proper hole and electron transport layers.