Fabrication of a light-emitting device based on the CdS/ZnS spherical quantum dots

Journal of the European Optical Society-Rapid Publications

Kobra Hasanirokh¹  Saber Mohammadi¹  Asghar Asgari² 

[1] Research Institute for Applied Physics & Astronomy, University of Tabriz, 51665-163, Tabriz, Iran;Research Institute for Applied Physics & Astronomy, University of Tabriz, 51665-163, Tabriz, Iran;School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 6009, Crawley, WA, Australia;

关键词: Colloidal quantum dot;    Light-emitting diodes;    Photoluminescence;    Absorbance;    Reverse micelle method;    Current density;   

DOI  :  10.1186/s41476-021-00173-8

来源: Springer

【 摘 要 】

In this work, we focus on the colloidal quantum dot based light-emitting diodes (QD-LEDs) performance. First, we synthesize the spherical QDs with a CdS core that covered with a wider band gap II–VI semiconductor acting as a shell (ZnS). In order to synthesize this nano crystal QDs with structure of CdS/ZnS/CdS/ZnS, we use a reverse micelle process. These four-layer quantum well quantum dots (QWQDs) can generate the white light emission. The positional design of different layers i.e., core/shell QD emitters is a critical factor for white emissive devices. The blue emission generated by CdS core mixes with green/orange components originating from ZnS inner shell and creates an efficiency white light emission. Then, we fabricate a white-QDLED with a device structure of FTO/ ZnO / QD / CBP/ MoO3 / Al films. A thin film of CdS/ZnS/CdS/ZnS QDs is deposited by electrostatically assembled colloidal QD solutions. The experimental results show that the emission spectra of QDs and current density through the LED are controlled by varying the particle sizes. The peaks of absorbance and Photoluminescence (PL) spectrums for core/shell structures get the red shifted as the dot size increases. Furthermore, this QD-LED with a smaller nano particle layer has a higher current density.

【 授权许可】

CC BY