In-Situ Growth of Silicon Nanowires Array and Its Field Emission Behavior

In-situ growth of silicon nanowires (Si-NWs) array on Si substrate has been obtained by a simple approach based on physical masking. A physical mask comprised of an array of laser drilled circular holes (diameter ~20 µm) onto a thin tungsten foil was used to pattern Tin (Sn) thin film, used as a catalyst. The Si-NWs were selectively grown on the patterned Sn islands using the hot filament chemical vapor deposition (HFCVD) method under optimized experimental conditions. The as-synthesized array of Si-NWs was characterized using field emission scanning electron microscope (FESEM), UV–visible, and Raman spectroscopy. The field emission (FE) characteristics of the Si-NWs array emitter were investigated at a base pressure ~1 × 10–8 mbar. The emitter showed turn-on and threshold field values of 1.8 and 2.2 V/µm, respectively, which are lower than those reported for un-patterned Si-NWs and similar emitters. Interestingly, the maximum emission current density of ~1058.63 µA/cm2 was extracted at a relatively lower applied field of 3.9 V/µm. Furthermore, the Si-NWs array emitter exhibited excellent emission stability at pre-set value ~1 µA over three hours duration. The results obtained herein clearly demonstrate the potential of the Si-NWs array emitter for practical applications in various vacuum micro-nanoelectronic devices.