Tailoring Contacts\nfor High-Performance 1D Ta₂Pt₃S₈ Field-Effect\nTransistors

Abstract

Materials with van der Waals (vdW) unit structures rely\non weak\ninterunit vdW forces, facilitating physical separation and advancing\nnanomaterial research with remarkable electrical properties. Recently,\nthere has been growing interest in one-dimensional (1D) vdW materials,\ncelebrated for their advantageous properties, characterized by reduced\ndimensionality and the absence of dangling bonds. In this context,\nwe synthesize Ta₂Pt₃S₈, a 1D vdW\nmaterial, and assess its suitability for field-effect transistor (FET)\napplications. Spectroscopic analysis and electrical characterization\nconfirmed that the band gap and work function of Ta₂Pt₃S₈ are 1.18 and 4.77 eV, respectively. Leveraging\nvarious electrode materials, we fabricated n-type FETs based on Ta₂Pt₃S₈ and identified Cr as the optimal\nelectrode, exhibiting a high mobility of 57 cm² V^–1 s^–1. In addition, we analyzed the electron transport\nmechanism in n-type FETs by investigating Schottky barrier height,\nSchottky barrier tunneling width, and contact resistance. Furthermore,\nwe successfully fabricated p-type operating Ta₂Pt₃S₈ FETs using a molybdenum trioxide (MoO₃)\nlayer as a high work function contact electrode. Finally, we achieved\nTa₂Pt₃S₈ nanowire rectifying diodes\nby creating a p–n junction with asymmetric contact electrodes\nof Cr and MoO₃, demonstrating an ideality factor of 1.06.\nThese findings highlight the electronic properties of Ta₂Pt₃S₈, positioning it as a promising 1D vdW\nmaterial for future nanoelectronics and functional vdW-based device\napplications.