Band gap engineering and photoluminescence studies of imine linked ZnO nanoparticles synthesized by direct precipitation route

An imine linked dipodal organic receptor 1 is synthesized using condensation reaction between 2-aminothiophenol and 4-diethylaminosalicylaldehyde which is used as a capping agent over ZnO resulting in surface modified ZnO nanoparticles 1.ZnO. The conjugate 1.ZnO shows emission at 420 nm. The emission spectra obtained from surface modified ZnO nanoparticles is pure and sharp with full width half maximum (FWHM) 60 nm in comparison to emission spectra of pure ZnO which shows emission at 434 nm, 456 nm and 520 nm. It is demonstrated that organic receptor 1 acted as a capping monolayer over ZnO semiconductor as the surface defects that otherwise resulted in electronic transitions has not shown emission at various wavelengths in visible range. Thus the capping agent has successfully passivated the ZnO nanoparticles. The synthesized 1.ZnO nanoparticles can be used in active layer of light emitting diode providing blue emission at 420 nm.