Effect of Electric Bias on the Deposition Behavior of ZnO Nanostructures in the Chemical Vapor Deposition Process

Abstract

Much evidence has been reported that charged nanoparticles are generated in the gas phase and contribute to film deposition or nanostructure formation in the chemical vapor deposition (CVD) process. Such a new way of crystal growth with nanoparticles as a building block is closely related to a recently discovered nonclassical crystallization, which has recently attracted great attention. It is often found that deposition does not occur on the substrate even when a huge amount of charged nanoparticles are generated in the gas phase. A drag force exerted on the nanoparticles would be one possibility for such nondeposition. To test such a possibility, an electric bias was applied to the substrate. Under the condition where no deposition occurred on a substrate at 450 °C, small ZnO nanoparticles were deposited on the substrate when 100 V of direct current (dc) was applied to the substrate. When the bias voltage was increased to 300 V, nanoparticles of a larger size were deposited. When the bias voltage was in...