Design of Sb2Te3 nanoblades serialized by Te nanowires for a low-temperature near-infrared photodetector

Abstract

The dangling bond on the surface of bulk materials makes it difficult for a physically contacted heterojunction to form an ideal contact. Thus, periodic epitaxial junctions based on Sb₂Te₃ nanoblades serialized by Te nanowires (Sb₂Te₃/Te) were fabricated using a one-step hydrothermal epitaxial growth method. X-ray diffraction and electron microscopy reveal that the as-prepared product has a good crystal shape and heterojunction construction, which are beneficial for a fast photoresponse due to the efficient separation of photogenerated carriers. When the Sb₂Te₃/Te composite is denoted as a photodetector, it shows superior light response performance. Electrical analysis showed that the photocurrent of the as-fabricated device declined with temperatures rising from 10K to 300K at 980 nm. The responsivity and detectivity were 9.5 × 10¹¹ μA W^-1 and 1.22 × 10¹¹ Jones at 50 K, respectively, which shows better detection performance than those of other Te-based photodetector devices. Results suggest that the as-constructed near-infrared photodetector may exhibit prospective application in low-temperature photodetector devices.

Keywords: epitaxial growth; heterojunction; low-temperature; photodetector; responsivity and detectivity.