Spectral and kinetic characteristics of ultrathin cadmium selenide nanoscrolls

We have studied the optical and luminescence properties at room temperature of ultrathin colloidal semiconductor cadmium selenide nanoscrolls with a thickness of 2.5 monolayers. For colloidal synthesis of the objects under study, cadmium acetate dihydrate Cd(CH3COO)2·2H2O and trioctylphosphine selenide were used as precursors of cadmium and selenium, respectively, and solutions of oleic acid and octadecene were also used. Luminescence spectrum of cadmium selenide nanoscrolls was recorded using a fiber charge coupled device spectrometer. Spectrally resolved photoluminescence decays for nanoparticles were measured with the use of time-correlated single photon counting technique. The emission of the cadmium selenide nanoscrolls consists of interband and recombination luminescence bands. We found that the normalized photon numbers of recombination luminescence are larger than the normalized photon numbers of interband luminescence. We determined dominant wavelengths, chromaticity coordinates, and correlated color temperatures of ultrathin colloidal semiconductor cadmium selenide nanoscrolls. These ultrathin cadmium selenide nanoscrolls are promising for application in light-emitting diodes.