Evaluation of field electron emission properties of ZnIn2S4 nanopetals grown on conducting carbon substrate

Abstract

The hierarchical structure of nanometric thick Zinc Indium Sulfide (ZnIn2S4) has been prepared on electrically conductive carbon cloth using a single step hydrothermal method. The surface morphology of the as-synthesized ZnIn2S4 (ZIS) is characterized with well interconnected criss cross-network of vertically oriented nanopetals. Owing to the unique morphology offering high aspect ratio, field emission (FE) characteristics of the hierarchical ZIS structure have been investigated at a base pressure of 1x10−8 mbar. Interestingly, the ZIS emitter exhibited ultralow values of turn-on and threshold fields, 0.84 and 0.95 V/μm, defined at 1 and 10 μA/cm2, respectively. Furthermore, maximum emission current density of 1.9 mA/cm2 has been obtained from the emitter at relatively lower applied field of 2.07 V/μm. The emission current stability tested at a pre-set value of ~5 and 10 μA over 4 h duration is observed to be very good. The superior FE characteristics are attributed to the high aspect ratio of the vertically oriented nanopetals, their excellent mechanical and chemical sturdiness, and intimate contact with the electrically conducting carbon fibers. The outcome of FE properties indicates the potential applicability of hierarchical ZIS nanostructure emitter, grown on carbon cloth and possessing unique morphology grown on carbon cloth in the practical application in FE based vacuum micro/nano-electronic devices.