Optical characterization of ZnO nanobelts

Abstract

Zinc oxide nanobelts have been synthesized by chemical precipitation technique using zinc acetate as starting material. Scanning electron microscopy observations indicate that the lengths of nanobelts are ranging from a few hundreds of micrometers to a few millimeters. X-Ray Diffraction pattern confirms the würtzite structure. Nitrogen laser is employed here as an excitation source (337.1 nm, 10 ns) for phosphorescence studies. From the decay curves of time resolved laser induced photoluminescence, various optical parameters such as Einstein’s spontaneous and stimulated coefficients, oscillator strength, integrated cross-section and dipole-moment of ZnO nanobelts have been calculated and reported in this paper. Einstein’s spontaneous and stimulated coefficient values obtained from the decay curves indicate the probability of transitions from various traps. Selective excitation of the levels can make ZnO as a best suited laser medium.