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

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.