Synthesis And Characterization Of Highly Emissive Solid-State Luminescent Carbon Dots And Their Applications

Luminescent carbon dots(CDs)is a new kind of carbon-based nano-luminescent materials developed in recent years.As a new material in the family of carbon materials,CDs was first discovered by scientists in 2004.And this new type of luminescent nano-material has attracted increased attentions for their superior optical properties in recent years.However,CDs generally suffer from aggregation-induced luminescence quenching,which means highly emissive in solution or dispersed state but dramatically quenched in solid or aggregated state.This problem significantly limits the practical application of CDs,partially in the solid-state light-emitting devices.In this work,a new kind of solid-state emissive CDs,which suppress the aggregation-induced luminescence quenching,have been synthesized via simple one-step hydrothermal strategy.Under 450 nm excitation,the CDs exhibit bright green luminescence in the solid state,with a quantum yield of 26% and short luminescence lifetime of 4 ns.Making use of the CDs as color converter,white light-emitting diodes were fabricated and a blue laser-based visible light communication with a modulation bandwidth up to 55 MHz and data transmission rate of 181 Mbps was demonstrated.In order to solve the problem of aggregation induced fluorescence quenching of most CDs,this thesis developed a new method for preparing solid-state luminescent CDs successfully and applied this solid-state luminescent CDs to lighting and visible light communication.The specific work is as follows:1.A new kind of solid-state emissive CDs,which suppress the aggregation-induced luminescence quenching,have been synthesized via simple one-step hydrothermal strategy.2.The structure and properties of the prepared CDs were characterized by instruments.3.According to the structure and properties of the prepared CDs,we tried to give an explanation of the luminescence mechanism of the CDs.4.Making use of the CDs as color converter,white light-emitting diodes were fabricated.5.Making use of the CDs as color converter,a blue laser-based visible light communication with a modulation bandwidth up to 55 MHz and data transmission rate of181 Mbps was demonstrated.