CdS nanowires: Ultra-long growth and enhanced field emission properties

Abstract

Here, we report the synthesis of ultra-long CdS nanowires with aspect ratio ∼8 × 104 by simple route of thermal evaporation technique. A change in the vertical arrangement of quartz boats leads in to the synthesis of ultra-long CdS nanowires via high degree of condensation. This technique is seen to be cost effective and easy. The growth of the nanowires is found to be increased very rapidly from few micrometers to few millimeters. The possible reason for the growth of the ultra-long CdS nanowires is discussed in detail. The turn-on field defined for the current density of ∼0.1 μA/cm2 has been found to be ∼1.4, 1.45, 1 and 0.17 V/μm for specimen A, B, C and D (specimens A–D, synthesized by variation in synthesis parameters) respectively. The turn-on field of the specimen D (∼0.17 V/μm) is found to be quite superior than the value reported for other CdS nanoforms which is very remarkable. Simple way of bulk fabrication leads to the low turn-on value which indicates a possible use of the present emitter in the micro/nanoelectronics devices.