Transparent Perovskite Light-Emitting Diodes with Conductive Oxide Top Electrodes

Transparent light-emitting diodes (TrLEDs) allow to simultaneous display data while maintaining the visibility of the surroundings. This feature unlocks a new range of applications. Perovskite-based emitting materials are promising for such devices in view of their narrow emission spectrum and color tunability. Here, we show that depositing an indium tin oxide (ITO) electrode using pulsed laser deposition in combination with a metal oxide buffer layer is a universal approach for the fabrication of transparent perovskite LEDs (TrPeLEDs) with a variety of compositions and device configurations. Green TrPeLEDs based on in situ formed perovskite nanocrystals (NC) deposited directly on ITO coated glass substrates achieved a record-high combined luminance of 150 000 cd m^-2. When instead a TrPeLED using a thin colloidal NCs layer was used it led to LEDs with an average visible transmittance of 80% and a color rendering index above 90.