Self-assembled ZnS nanowire arrays: synthesis, in situ Cu doping and field emission

Well-aligned single-crystalline ZnS nanowire arrays have been grown on highly conductive Cu substrates through controlling the morphology evolution of self-patterned ZnS nanoparticles. The ZnS nanowires have sharp tips with an average size of approximately 30 nm and a length of approximately 3 microm. Field emission measurements demonstrated that the aligned ZnS nanowires grown on Cu substrates are excellent field emitters having a turn-on field as low as 2.92 V microm(-1) and a field-enhancement factor as high as 3400. The use of highly conductive metal substrate may promote the commercial applications of ZnS-based emitters in flat panel displays and other optoelectronic devices.