Heterostructures of MoS2 nanofilms on TiO2 nanorods used as field emitters

Heterostructures of 2-dimensional (2D) layered MoS2 nanofilms on ordered 1-dimensional (1D) TiO2 nanorods (MoS2@TiO2 heterostructures) are synthesized on Si substrates using a simple and low-cost hydrothermal method and then used as field emitters. Results of comparative experiments show that the MoS2@TiO2 heterostructures outperform the as-synthesized 1D TiO2 nanorods in field emission. This advantage is mainly attributed to three factors. First, in MoS2@TiO2 heterostructures, besides the high aspect ratio of the TiO2 nanorods, the sharpness of the MoS2 layer edges also contributes to the enhancement of the local electric field. Second, the large number of the MoS2 layer edges gives rise to more emission sites. Third, more electrons are available in the conduction band of MoS2.