Vertically Aligned Te Nanowire Array Growth by Geometric Confinement

Abstract Tellurium nanowires have demonstrated great potential for various applications, such as thermoelectric devices, optoelectronics, and biosensors, due to their excellent electronic, thermal, and optical properties. However, lacking an effective method to prepare vertically aligned and uniformly distributed tellurium nanowire arrays is a bottleneck for their practical applications. In this study, we successfully fabricated aligned tellurium nanowires (A-Te NWs) on a Pt/polyimide/glass substrate using a seedless chemical liquid-phase method. Pt square arrays were employed as the catalytic layer to define patterned selective growth regions on the polyimide/glass substrate. Such geometric confinement of growth proves highly effective in promoting the vertical ordering of A-Te NWs. Moreover, the verticality and density of A-Te NWs highly depend on the Pt pattern size. Specifically, smaller patterns result in denser and more vertical A-Te NWs due to their lower surface roughness. In addition, the Pt layer thickness and liquid-phase reaction conditions for the growth of A-Te NWs have been optimized to yield densely packed and vertically aligned A-Te NWs, with a Pt layer thickness of 3 nm, a reaction time of 6 h, a reaction temperature of 30 °C, a pH of 10, a hydrazine hydrate amount of 2 mL, and a cetyltrimethylammonium bromide concentration of 5 mM. Our work paves the way for the practical applications of tellurium nanowires.