Highly stable and bright blue light-emitting diodes based on carbon dots with a chemically inert surface

Tianyang Zhang; Xiao Wang; Zhenyu Wu; Tianyu Yang; Han Zhao; Jiawei Wang; Hui Huang; Yang Liu; Zhenhui Kang

doi:10.1039/d1na00576f

Highly stable and bright blue light-emitting diodes based on carbon dots with a chemically inert surface

Nanoscale Adv. 2021 Oct 4;3(24):6949-6955. doi: 10.1039/d1na00576f. eCollection 2021 Dec 7.

Authors

Tianyang Zhang¹, Xiao Wang¹, Zhenyu Wu¹, Tianyu Yang¹, Han Zhao¹, Jiawei Wang¹, Hui Huang¹, Yang Liu¹, Zhenhui Kang^{1

2}

Affiliations

¹ Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Soochow University Suzhou 215123 China zhkang@suda.edu.cn yangl@suda.edu.cn.
² Macao Institute of Materials Science and Engineering, Macau University of Science and Technology Taipa 999078 Macau SAR China.

Abstract

The manufacture of blue light-emitting diodes (LEDs) has always been a tough problem to solve in the display and illumination fields. Inorganic/organic semiconductors and carbon dots (CDs) with a wide band gap still face obstacles such as a low external quantum efficiency (EQE) and poor stability. Herein, we synthesized highly stable and blue emission CDs with a chemically inert surface, and the photoluminescence (PL) peak (in ultra-pure water) of which is located at 446 nm with an absolute PL quantum yield (PLQY) of 26.4%. The LEDs based blue emission CDs exhibit an electroluminescence (EL) peak located at 456 nm and a high brightness of 223 cd m^-2 with an EQE of 0.856%. The Commission Internationale del'Eclairage (CIE) coordinates are located at (0.21, 0.23) and the device lifetime with 65% brightness (T ₆₅) reaches over 217 h because of the chemically inert surface of the CDs. The results mean the devices are the most stable CDs-LEDs reported to date. This work represents a novel route for the preparation of low cost, highly stable and very bright CDs-LEDs with a short wavelength emission.