Influence of Sb as a catalyst in synthesize of Sb doped ZnO nanostructures using nanoparticle assisted pulsed laser deposition for UV led applications

Abstract

The paper deals with synthesis of Sb and Sb-Al co-doped ZnO nanowires using nanoparticle assisted pulsed laser deposition (NAPLD) by considering Sb as a catalyst. The mechanism of the growth initiation of nanostructures from the Sb droplets is analyzed at varying growth temperature. Nanowires and nanosheets of different orientation were synthesized. With ZnO:Al target and Sb coated Si as substrates, at a growth temperature of 750 °C, random oriented high density nanowires with a diameter of about 1 μm and a length up to a few tens of micrometer were synthesized. The suppression of A1T modes and E1(L0) modes from Raman spectroscopy confirming that depletion of oxygen vacancies. XPS analysis confirming that the Sb would substitute for Zn(Sbzn) instead of oxygen Al-O bonds, leading to excess of oxygen, neutralizing the oxygen vacancies. The Sb-Al co-doped nanowires annealed at 650 °C showed a strong UV emission and reduction in visible emission as compared to the Sb-Al co-doped nanowires annealed at 450 °C. This confirms that the Sb-Al co-doped posses high stoichiometric nature, good structural and optical properties. To investigate the p-type conductivity of the Sb-Al co-doped nanowires, a homo p-n junction was prepared by synthesizing Sb-Al co-doped ZnO nanowires on the pure ZnO surface. The I-V characteristics of the homo P-N junction were investigated and a rectifying behavior was observed confirming the formation of p-type. Hence the Sb mono-doped and co-doped ZnO nanowires synthesized by using Sb as catalyst posses good structural and optical properties with good crystallization quality and high stoichiometry nature, hence it is highly suitable for light emitting device applications. © Springer India 2014.