Insight into TaSi₂ Nanostructures with Different Morphologies and Their Field Emission Properties

Abstract

Recognizing the strong potential of cold cathodes for important commercial applications in fields such as electronics, there is a growing interest in the exploration of novel 1D nanomaterials. Among various cold cathode materials, TaSi2 is of great interest for its outstanding field emission performance. In this work, the Si‐TaSi2 eutectic composite with nano‐sized highly oriented TaSi2 fibers and semi‐coherent phase interfaces is prepared by the laser floating zone melting technique with a very high‐temperature gradient of 6000 K cm−1 at a solidification rate of 200 µm s−1. On the basis of directionally solidified Si‐TaSi2 eutectic composite, well‐aligned TaSi2 nanorod and nanotip arrays are fabricated by inductively coupling plasma (ICP) etching process and HNO3/HF wet etching process, respectively. The field emission measurements show that the field enhancement factor, turn‐on electric field, and effective work function are strongly affected by tip morphologies. The TaSi2 array with regular nanotip structure possesses the best field emission characteristic among all TaSi2 nanostructures, with a relatively low turn‐on field of 4.8 V µm−1 and a high current density of 733 µA cm−2. These findings preliminarily establish a clear relationship between the performance and structure of the array, providing technical guidance for the application of this material in electronic devices.