Studies Of Lead Halide Perovskite Nanocrystals Electrochemiluminescence Based On Interface Construction

Lead halide perovskite nanocrystals(LHPNCs)have excellent optical properties,such as narrow band emission,high fluorescence quantum yield,adjustable band gap width and adjustable emission wavelength.In recent years.it is emerging in the field of electroluminescence(ECL).Due to intrinsic ionic salt properties of LHPNCs,it is unstable in polar solvent which is a key issues.In addition,the current studies are focus more on the electrochemical behavior of LHPNCs ECL,and do not give much consideration on the design of interface engineering that significantly affects the ECL performance.From this perspective,the interface behavior of LHPNCs ECL comes to the main point in this dissertation,which combines with more stable design of materials.This dissertation contains the following five chapters.Chapter I.the overview of mechanism and forefront of ECL.Moreover,the properties of lead halide perovskite nanocrystals and their current research in ECL are introduced in detail.Chapter 2,three phase interface contains glassy carbon(conductive medium)CsPbBr3 PNCs(ECL luminophores)and acetonitrile(electrolytes)has been constructed as bridges to connect the three series of ECL process.The results verify stronger signal of ECL matches with more three phase interface.Finally,a seven-fold signal enhancement has been achevied.Chapter 3,micro three-phase interface has been constructed using CsPbBr3 PNCs immobolizing on nitrogen-carbon materials,by which the film is easier to form and lower impedance could be obtained comparing with the pure CsPbBr3 PNCs.Moreover,the carbon materials are of rich in nitrogen functional groups that can passivate PNCs,lead to more stable construction of PNCs.By this way,the luminophores is stable under electrical stimulation,the ECL signal maintains in a stable state and film layer without significant collapse after the ECL tests.Chapter 4,the optimization of micro three-phase interface has been investigated.The duration and temperature of incubation are regulated.OAm content of CsPbBr3 PNCs and nitrogen content of the carbon material are adjusted.Stable emission of 37.5k a.u could be obtained in acetonitrile solution containing 10 mmol/L TPrA,and the RSD of 15 response cycles is 3%.In the detection of copper oleate,high sensitivity response with amol level is achevied.Chapter 5,a summary of this dissertation and put forward perspectives on this subject.