Highly stable cesium lead iodide perovskite quantum dot light-emitting diodes

Authors:

Abstract
Recently, all-inorganic perovskites such as CsPbBr 3 and CsPbI 3 , have emerged as promising materials for light-emitting applications. While encouraging performance has been demonstrated, the stability issue of the red-emitting CsPbI 3 is still a major concern due to its small tolerance factor. Here we report a highly stable CsPbI 3 quantum dot (QD) light-emitting diode (LED) with red emission fabricated using an improved purification approach. The device achieved decent external quantum efficiency (EQE) of 0.21% at a bias of 6 V and outstanding operational stability, with a L 70 lifetime (EL intensity decreases to 70% of starting value) of 16 h and 1.5 h under a constant driving voltage of 5 V and 6 V (maximum EQE operation) respectively. Furthermore, the device can work under a higher voltage of 7 V (maximum luminance operation) and retain 50% of its initial EL intensity after 500 s. These findings demonstrate the promise of CsPbI 3 QDs for stable red LEDs, and suggest the feasibility for electrically pumped perovskite lasers with further device optimizations.
Funding Information
  • The Center for Advanced Solar Photophysics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences
  • NASA Space Technology Research Fellowship (#NNX13AL60H)
  • Ministry of Science and Technology, Taiwan (105-2811-M-029-003)

This publication has 35 references indexed in Scilit: