Morphological Dependence of Field Emission Properties of Silicon Nanowire Arrays

Abstract

The electron field emission (EFE) properties of vertically aligned arrays of silicon nanowires (SiNWs) grown from silicon substrate at different gold sputtering periods of 0[Formula: see text]s, 8[Formula: see text]s, 15[Formula: see text]s and 25[Formula: see text]s at a rate of 10[Formula: see text]nm/min by electroless metal deposition process were investigated. It has been observed that the transformation of silicon tips from irregular to highly dense and uniform cylindrical morphological nanostructures with an increase in Au sputtering periods. A significant enhancement in EFE properties of as-prepared arrays of SiNWs with the increase in Au sputtering periods is observed. The threshold fields for attaining current density of 0.1[Formula: see text]mA[Formula: see text][Formula: see text] were decreased gradually as 32.38[Formula: see text][Formula: see text], 29.37[Formula: see text][Formula: see text] and 23.19[Formula: see text][Formula: see text] for the arrays of SiNWs synthesized from Si substrate by Au coating of 8[Formula: see text]s, 15[Formula: see text]s and 25[Formula: see text]s respectively. Moreover, from Fowler–Nordheim plot, the turn-on field is observed to decrease from 16.56[Formula: see text][Formula: see text] for as-prepared to 8.77[Formula: see text][Formula: see text] for 25[Formula: see text]s Au sputtered SiNW arrays. The effective work functions of the electron emitting array of SiNWs have been improved from 0.5[Formula: see text]meV to 0.1[Formula: see text]meV.