摘要
Electrogenerated chemiluminescence(ECL)has been extensively used in ultrasensitive electroanalysis because it can be generated electrochemically without using expensive optics and light sources.Visible ECL emission can be obtained with a reasonable quantum yield and stability.Blue ECL is rare and often suffers from stability and poor quantum efficiency.Blue ECL emission at 473 nm from organometallic halide perovskite nanocrystals(PNCs),CH_(3)NH_(3)PbCl_(1.08)Br_(1.92),is reported here for the first time using tripropylamine(TPrA)as co-reactant.The blue ECL emission peak resembles its photoluminescence peak position.In addition to this blue emission peak,the ECL spectra of CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs also showed a broad ECL peak at 745 nm.Generation of the second ECL peak at 745 nm from CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs was can be explained by the existence of surface trap states on as-synthesized PNC due to incomplete surface passivation.Halide anion tunability of ECL emission from CH3NH3PbX3(X:Cl,Br,I)PNCs is also demonstrated.The fluorescence microscopy image of single PNC and stability of selected single PNCs are presented in this with simultaneous acquisition of fluorescence spectra using 405-nm laser excitation.The photoluminescence(PL)decay was described by PL lifetime(τ)of 1.2 ns.The effect of the addition of surfactants(oleic acid and n-octylamine)on the fluorescence intensity and stability of CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs is also discussed.
基金
We would like to thank the financial support from the National Science Foundation(NSF award CHE 1508192 and OIA-1539035).
