CsPbBr3-Cs4PbBr6 composite nanocrystals for highly efficient pure green light emission.
Miao He1, Chunyun Wang2, Jingzhou Li2
1Key Laboratory of Polar Materials and Devices (MOE) and Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai 200241, China. jzzhang@ee.ecnu.edu.cn.
Nanoscale
|November 26, 2019
Summary
All-inorganic perovskite composite nanocrystals offer a convenient route to efficient green phosphors for light-emitting diodes (LEDs). These materials achieve high photoluminescence quantum yield, enhancing LED brightness and stability.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Optoelectronics
Background:
- All-inorganic perovskite nanocrystals (NCs) are promising for optoelectronic applications.
- Developing efficient and stable green phosphors for LEDs remains a challenge.
Purpose of the Study:
- To synthesize and characterize CsPbBr3-Cs4PbBr6 composite NCs as green phosphors for LED applications.
- To investigate the optical properties and performance of these composite NCs in solid-state devices.
Main Methods:
- Convenient solution synthesis of CsPbBr3-Cs4PbBr6 composite NCs without inert gas protection.
- Characterization of colloidal NCs and thin films using photoluminescence spectroscopy.
- Fabrication and testing of green LEDs incorporating the composite NCs.
Main Results:
- Colloidal composite NCs exhibit green emission around 515 nm with a high photoluminescence quantum yield (PLQY) of 74%.
- Thin films show a slight redshift due to aggregation, but LEDs achieve Commission Internationale De I'eclairage (CIE) chromaticity coordinates of (0.201, 0.746).
- Green LEDs demonstrate a luminous efficiency of 45 lm W-1 at 10 mA, with improved brightness and stability attributed to the composite structure.
Conclusions:
- The CsPbBr3-Cs4PbBr6 composite NCs are effective green phosphors for LED applications.
- The passivation effect of the Cs4PbBr6 matrix on CsPbBr3 NCs suppresses nonradiative recombination, leading to high PLQY.
- These composite perovskites offer a promising strategy for developing high-performance pure green LEDs.
