Rapid synthesis of AgInS2 quantum dots by microwave assisted-hydrothermal method and its application in white light emitting diodes

• Published in: Journal of alloys and compounds 2023-01, Vol.930, p.167389, Article 167389
• Main Authors: Chen, Yuanhong, Chen, Ting, Qin, Zhe, Xie, Zhixiang, Liang, Mengbiao, Li, Youpeng, Lin, Jian
• Format: Article
• Language: English
• Subjects: AgInS2 quantum dots; Color temperature; Ionic liquids; Light emitting diodes; Luminescence; Luminous efficacy; Microwave assisted-hydrothermal method; Optical properties; Phosphors; Photoluminescence; Photoluminescence quantum yield; Quantum dots; Reaction time; Surface coating; Synthesis; White light; WLEDs; Zinc sulfide
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.167389

Rapid synthesis of AgInS2 quantum dots (AIS QDs) with high quantum yield and crystallinity in aqueous phase has been identified as a research priority in the realm of colloidal semiconductors. Herein, microwave assisted-hydrothermal method was used to react for 5 min at 120 °C to prepare AIS QDs with high luminescence properties. Meanwhile, 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) ionic liquid (IL) was employed as a wave absorber to enhance the photoluminescence quantum yield (PLQY) and shorten the reaction time. The AIS QDs exhibited spectral tunability by adjusting the IL/AgIn molar ratio from 0 to 10, and the luminescence peak position could be tuned from 597 nm to 670 nm. The PLQY of AIS QDs reached 27.67% at the IL/AgIn molar ratio of 2.5, and the fluorescence lifetime upped to 360.4 ns. In addition, the ZnS shell was coated on the surface of the QDs with Zn/AgIn= 3 by reacting at 90 °C for 2 min, and the PLQY could reach to 35.66%, which further improved the emission performance of the AIS QDs. Finally, QDs and commercial (Ba, Sr)Si2O2N2:Eu2+ phosphors were mixed to fabricate white light emitting diodes (WLEDs) devices. AIS@ZnS QDs-based WLED showed color rendering index (CRI) of 87.7 and correlated color temperature (CCT) of 5220 K. And its luminous efficiency (LE) reached 80.13 lm/W, which is 2.16 times higher than that of AIS QDs-based WLED (37.1 lm/W), indicating the good application prospect in WLEDs. [Display omitted] •AgInS2 QDs are prepared via microwave assisted-hydrothermal method within 5 min.•The PLQY of the water-soluble AgInS2 QDs is 27.67%.•The emission peak is tuned from 602 nm to 573 nm by adjusting the Ag/In ratio.•The luminous efficiency of QDs-based WLED is 80.13 lm/W.