Towards Efficient and Stable Perovskite Light Emitting Diodes

Perovskite LEDs are an exploding field, with high performance red and green devices demonstrated by many groups. However, two key challenges towards commercialization remain: poor performance at higher energies, and poor overall stability (particularly at those higher energies). Here, we demonstrate investigations into both issues. First, we identify two crucial issues holding blue materials back: the low internal photoluminescence yield and the LED device structure itself. By rectifying these issues, we were able to build LEDs that were 60x brighter than control, and, when combined with red and green downconverters, white light emitting LEDs. We further demonstrate how careful control over fabrication conditions allows for more uniform thin films, creating violet LEDs with 5x the efficiency over control devices. Finally, we study the interplay between efficiency and stability in green LEDs, showing that while an additive material can increase efficiency, it also leads to a stability decrease, highlighting the need for global evaluation of these changes to the device composition.