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 H 2 Te 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.