One-dimensional semiconductor nanostructures: growth, characterization, and device applications

摘要

Molecule-based CVD is applied for the development of 1D semiconducting nanowires. By virtue of the chemical design of the metal-organic precursors, it is possible to achieve the required supersaturation ratio of phase-constituting elements in the gas phase, which allows to grow anisotropic structures with precisely controlled dimension and composition. [Ge(C5H5)2] with labile Ge-C bonds was thermolysed at 300 °C to grow single crystalline Ge nanowires (NWs). For tin oxide nanostructures, [Sn(OBut)4] with relatively strong and preformed Sn-O bonds was employed to synthesize anisotropic rutile phase. Determination of I-V characteristics of Ge NWs in different environments indicate surface passivation, possibly through hydrogen. Radial dimension of SnO2 NWs was varied in the range 30-1000 nm by choosing appropriate size of catalyst particles. Photo-conductance studies on different NW samples revealed a significant 'blue shift' with shrinking wire diameters. Tin oxide nanowires were coated with vanadium oxide by CVD of [VO(OPri)3] on as-grown tin oxide nanowires. Composite SnO2/VOx 1D nanostructures showed a shift to higher wavelength in photo-response peak, when compared to pure SnO2 NWs. We also demonstrate the integration of single NW on pre-patterned electrodes for evaluating sensing and electrical properties on individual nanoobjects.