SPECTRAL STABILITY OF CDSE/ZNS QUANTUM DOTS

The photoluminescence (PL) and photoluminescence excitation (PLE) spectra of CdSe/ZnS nanocrystal are measured using UV-visible Spectrophotometer and based on fluorescence spectroscopy we discuss the effects of excitation wavelength. concentration, temperature and deposited period on the spectra. With a long excitation wavelength, the peak wavelength of emission hand shows, a slight red left (4nm) related to the size distribution of the nanocrystal. The absorption peak wavelength is kept unchanged, and its intensity is enhanced as the concentration of CdSe/ZnS solution increases. A comparison of spectra of CdSe/ZnS nanocrystal carried out at interval of three months shows little change. With the increased temperature of the toluene solution from 333K to 373K. the first absorption peak wavelength redshifts similar to 1nm, while the emission peak wavelength redshifts similar to 3nm.