Investigation of temperature-dependent field emission from single crystal TiO2 nanorods

Temperature-dependent field emission (FE) of single crystal TiO2 nanorods has been investigated. It is found that the FE properties of TiO2 nanorods are critically affected by environmental temperature of emission tests. As the temperature increases from 290 to 500 K, the turn-on field decreases from 2.16 to 1.76 V/μm, whereas the current density increases. In addition, the physical mechanism of temperature dependence of FE is discussed in detail based on the variation of effective work function, which decreases from 4.3 to 3.64 eV with the temperature rise from 290 to 500 K. It is considered that the reduction of turn-on field and the enhancement of current density are mainly caused by the decrease of effective work function of the emitter.