Majority carrier transport in single crystal rutile nanowire arrays

Abstract magnified image Monocrystalline n‐TiO₂ nanowires of the rutile phase (Rtl‐NWs) grown by a scalable hydrothermal method constitute a functional oxide nanomaterial with potential applications in photovoltaics, photocatalysts, field emitters and electrochemical battery anodes. Carrier transport in Rtl‐NWs is of fundamental importance but has hitherto been inferred indirectly via impedance and intensity‐modulated spectroscopic techniques. We report an effective electron drift mobility of 1.95 × 10^–5 cm² V^–1 s^–1 in rutile nanowire arrays directly measured using the time‐of‐flight (TOF) and space charge limited current techniques. In addition, we measure an equilibrium free electron concentration of ∼10¹⁴ cm^–3 and a trap density of 3.5 × 10¹⁶ cm^–3 in rutile nanowires. These results point to the importance of reducing traps to improve charge transport in rutile nanowires. magnified image Transient photocurrents in rutile nanowires. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)