Sub-5-Min Ultrafast Growth of Millimeter-Scale-Length Tellurium Nanowires With Broadband Bulk Photovoltaic Response.

Abstract

Bulk photovoltaic effect (BPVE) featured by polarization-dependent photoresponse at zero external bias exhibits huge potential for exploiting next-generation photodetectors. However, the BPVE is mainly limited in the wide-bandgap ferroelectrics and complex van der Waals (vdW) heterostructures and scarcely demonstrated in narrow-bandgap vdW semiconductors. Here we develop a surface self-limiting diffusion driven growth strategy to rapidly synthesize millimeter-scale-length narrow-bandgap tellurium (Te) single-crystal nanowires with highly uniform non-centrosymmetric structure. The sub-5-min ultrafast growth-a feat not realized in prior Te synthesis arises from ultralow self-limiting diffusion and nucleation barriers of H₂Te precursors in a hydrogen-assisted space-confined environment. The fabricated photodetectors show broadband BPVE response from 520 nm to 4.6 µm, ultrahigh peak responsibility of 220 A/W and blackbody responsivity of 2.3 A/W, which are far superior to the state-of-the-art self-powered vdW devices. Furthermore, we demonstrate high-resolution polarization imaging and BPVE detector arrays in a single Te nanowire. This work opens perspectives of ultralong Te nanowires with robust BPVE for the development of high-performance on-chip integrated multidimensional photodetection systems.