Journal of Shanghai University(Natural Science Edition) ›› 2021, Vol. 27 ›› Issue (5): 846-855.doi: 10.12066/j.issn.1007-2861.2186

• Research Articles • Previous Articles     Next Articles

Synthesis of alloyed In$_{{\bf 1-}x}$Ga$_{x}$P quantum dots and their application to LEDs

YE Haiqiao, CAO Fan, DOU Yongjiang, YANG Xuyong()   

  1. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200444, China
  • Received:2019-09-20 Online:2021-10-31 Published:2021-10-22
  • Contact: YANG Xuyong E-mail:yangxy@shu.edu.cn

Abstract:

As alternatives to quantum dots based on cadmium, a toxic heavy metal, low-toxicity indium phosphide quantum dots (InP QDs) have shown excellent potential for application in next-generation commercial displays and illumination devices. However, the synthesis of InP QDs with high photoluminescence quantum yields (PL QYs) remains challenging. Therefore, the use of gallium acetylacetonate is proposed as a gallium source to activate surface ligands via acetylacetone at a high temperature to form In$_{1-x}$Ga$_x$P/ZnSe/ZnS with a gradient alloyed core, effectively solving the lattice mismatch between InP and ZnSe. Meanwhile, the gradient alloyed core can reduce the defects among interfaces, such that the PL QY of quantum dots is up to 82% and the external quantum efficiency of the prepared quantum dot light-emitting diode (QLED) reaches 3.1%. Compared to QDs with the traditional InP/ZnSe/ZnS structure, the In$_{1-x}$Ga$_x$P/ZnSe/ZnS QDs yield a PL QY enhancement of 25%, and the external quantum efficiency of the device is nearly doubled. This scheme provides a new method for solving the problems of lowPL QY of InP QDs and poor performance of light-emitting devices.

Key words: InP quantum dot (InP QD), gradient alloy core, ligand activation, quantum dot light-emitting diode (QLED)

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