Semiconductor Nanowire Doping: Controlling Magnetic and Electronic Properties of Colloidal Nanowares

Electronic devices have been utilized in a wide range of applications, such as computing, data storage, sensors, lightings, energy production, and energy storage; they are building blocks of computer processors, solid state data storage devices, image sensors in digital cameras, LEDs, and solar cells, etc. These electronic devices operate based on properties of semiconductors, which are their essential components. Not only being fundamental components of electronic devices, semiconductors can be crucial materials for other applications, such as catalysts, battery electrodes, etc. One of the primary current quest on semiconductor research is to develop semiconducting materials that are more compact and more efficient than existing materials. Science and technology for nanoscale materials has been applied to develop nanoscale semiconducting materials to complete the quest. One of the promising nanoscale semiconducting materials is semiconductor nanowire; its geometry and properties allow for several advantages. One of the challenges preventing semiconductor nanowire from practical usage is the insufficient technology to control its properties. This dissertation presents novel practical approaches to control magnetic and electronic properties of semiconductor nanowires via doping. First, preparation method of Mn(II) doped CdSe nanowires via nanocrystal diffusion doping mechanism and the effect of manganese doping as well as ligand exchange on magnetic property of Mn(II) doped CdSe nanowires are discussed. Moreover, indium doping on CdSe nanowires via sequential nanocrystal diffusion doping and cation exchange and its effect on electronic property of CdSe nanowires are demonstrated. Finally, an effort to use photochemical doping method to control electronic property of CdSe nanowires is presented here