The future is blue (LEDs): why chemistry is the key to perovskite displays

In this perspective, we review the recent work on metal halide perovskite light-emitting devices (peLEDs) with a focus on current challenges and the prospect of commercialization of perovskite displays. Metal halide perovskites have shown remarkable hole and electron mobilities, high photoluminescence quantum yield and color tunable, thin linewidth emission peaks making them ideal materials for the emissive layer in LEDs. Red and green emitting perovskites have already achieved very high external quantum efficiencies of greater than 20 % in the last year and may be ready to begin the commercialization process. However blue peLEDs still lag behind in efficiency and stability. After reviewing recent attempts to improve the blue peLED efficiency, we then list the current challenges in the field and suggest possible avenues of future research, including improvements in materials chemistry and device architecture. In particular, we find that advancements are needed in color stability and lifetime, by using dop...