Characterization of Carrier Dynamics in Metal Oxide Nanostructures and Tellurophenes

Abstract

Research was undertaken into the charge carrier dynamics of TiO2 nanotube and nanowire structures, which have potential in many technological applications and are already used in solar cells, OLED’s, photocatalysts, and biomedical applications. Using a combination of Time of Flight, Photoconductivity, IV, CV, and Time Resolved Microwave Conductivity, the charge carrier dynamics of TiO2 nanostructures were measured and later improved upon using a self-assembled monolayer surface for passivation, with mobility improving by a factor of almost 1000. The Time of Flight and Time Resolved Microwave Conductivity are explained in detail and can be used quickly, easily, and with a wide variety of materials to measure important material properties that are difficult to find using other methods. Organic Tellurophenes were also investigated using quantitative photoluminescence (PL) measurements such as quantum yield measurements and time resolved photoluminescence. The Tellurophenes were previously uncharacterized and only available in small quantitites. They were found to have unique properties such as triplet-decay leading to phosphorescent light emission which was tunable and with a relatively high quantum yield. The Tellurophenes were also found to have relatively high carrier mobilities after doping as high as 1.1×〖10〗^(-4) 〖cm〗^2 V^(-1) s^(-1).