Perovskite/organic hybrid tandem light-emitting diodes with an external quantum efficiency of over 40%

Abstract

Perovskite light-emitting diodes (PeLEDs) have been attracting widespread attention owing to their unique advantages such as high luminance, narrow emission spectra and high color purity. However, the solution-processed fabrication method makes the deposition of multi-emitting layers of perovskite films for white PeLEDs challenging. Moreover, modulating the emission color by adjusting the thickness of the emitting layers will result in reduced optoelectronic performance of the polycrystalline perovskite films. Therefore, strategies for achieving high-performance white PeLEDs are urgently needed. This study developed a newly designed perovskite/organic hybrid tandem light-emitting diode (POTLED) by combining a bottom PeLED unit with a top organic light-emitting diode (OLED) unit. The vacuum deposition process of the OLED avoids damaging the underlying PeLED unit. Additionally, the emission color of the tandem device can be tuned by adjusting the thickness of the organic emitting layer while maintaining the optoelectronic properties of the perovskite layer. As a result, a high-efficiency green POTLED with an outstanding current efficiency of 144.2 cd A⁻¹, an external quantum efficiency of 41.1%, and a luminance of over 32 000 cd m⁻² is achieved, illustrating the feasibility and potential of the hybrid tandem perovskite-organic structure to realize high-efficiency white-color perovskite-based devices.