Precursor-dependent shape variation of wurtzite CdSe crystals in a microwave-assisted polyol process

Abstract

We report a unique synthetic approach to fabricate CdSe crystals with tunable morphology and optical properties via a microwave-assisted polyol process. The morphology of CdSe crystals has been controlled by adjusting the relative amounts of two cadmium precursors CdCl₂ and CdO in a polyol solvent of ethylene glycol or glycerol; spheres, pebbles, sheets, and tetrapods of CdSe wurtzite structures with their sizes ranged from nanometers to sub-micrometers have been prepared facilely under microwave irradiation. The growth mechanism is discussed in terms of the LaMer theory; the nucleation and growth kinetics of CdSe, which depends decisively on cadmium precursors and polyol solvents, determines the shapes and sizes of diverse CdSe crystals.