Photophysical properties of nitrogen-doped carbon quantum dots synthesized by graphite  

作　　者：Jia Liu Hailong Yu Guan Wang Shuang Yang Meichen Li Xin Zhang Yang Jia Yachen Gao 

机构地区：[1]School of Electronic Engineering,Heilongjiang University,Harbin,150080,Heilongjiang,China [2]College of Communication and Electronic Engineering,Qiqihar University,Qiqihar,161000,Heilongjiang,China

出　　处：《Journal of Materiomics》2024年第4期828-836,共9页无机材料学学报（英文）

基　　金：This paper is grateful for the Natural Science Foundation of Heilongjiang Province(LH2020F041);Fundamental Research Funds in Heilongjiang Provincial Universities[145209148].

摘　　要：Here,nitrogen-doped carbon quantum dots(N-CQDs)were successfully synthesized by the solvothermal method using graphite as the carbon source and N,N-dimethylformamide as the nitrogen source.We characterized the structure and chemical constitution of N-CQDs using X-ray diffraction,Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy.We investigated the pump-and temperature-dependent photoluminescence(PL)properties and the dynamic exciton recombination processes of N-CQDs,using both steady-state and time-resolved PL techniques.The spectral results show that the PL emission peak located at 518 nm at room temperature,mainly originates from the n-π∗transition on the surface of N-CQDs.The pump fluence and PL integral intensity were analyzed to demonstrate the existence of single-photon excitation under the 405 nm laser excitation.As the temperature increases,the non-radiative transition gradually increases,which decreases the PL intensity,the full width at half maxima first narrows and then widens and the PL lifetime gradually decreases.Furthermore,we combined the N-CQDs with chip to prepare light-emitting diode(LED).The resulting chromaticity coordinate was obtained to be(0.29,0.40).This study offers a comprehensive understanding of the luminescence mechanism in N-doped CQDs and introduces a novel approach for the quickly fabrication of full-color display LEDs.

关 键 词：Carbon quantum dots NITROGEN-DOPED PHOTOLUMINESCENCE TEMPERATURE-DEPENDENT Non-radiative transition 

分 类 号：O61[理学—无机化学]