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/mu m, 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. (C) 2012 Elsevier B. V. All rights reserved.

对单晶TiO₂纳米棒的温度相关场发射（FE）进行了研究。研究发现，TiO₂纳米棒的场发射特性受到发射测试环境温度的严重影响。随着温度从290 K升高到500 K，开启电场从2.16 V/μm降低到1.76 V/μm，而电流密度则增加。此外，基于有效功函数的变化详细讨论了场发射温度相关性的物理机制，随着温度从290 K升高到500 K，有效功函数从4.3 eV降低到3.64 eV。据认为，开启电场的降低和电流密度的提高主要是由发射体有效功函数的降低引起的。（C）2012 Elsevier B.V. 保留所有权利。