Controlled growth of high-quality β-Ag2Se nanowires and their applications in near-infrared photodetection

Abstract

This work reports the controlled growth of single-crystalline β-Ag2Se nanowires and their application in near-infrared photodetection. High-quality Ag2Se nanowires with an orthorhombic crystal structure are grown via the chemical vapor deposition method with a length up to 32.8 μm and a diameter down to 52.1nm. By fine-tuning the growth parameters such as total tube inner pressure and precursor temperature, the length of Ag2Se nanowires can be precisely controlled. A dynamic growth model is also introduced to interpret the growth mechanism of Ag2Se nanowires. Two-terminal photodetectors based on single Ag2Se nanowire are fabricated and show competitive photodetection performance compared to that of other silver chalcogenide nanomaterial-based photodetectors. At room temperature, the fabricated Ag2Se nanowire-based photodetector exhibits a broadband response range of 400 - 1064nm at a bias voltage of 2V, while the peak photo-response performance is obtained in the near-infrared region. Under 830nm light illumination, the maximum responsivity, specific detectivity, rise time and decay time are measured and calculated to be 99.6mA/W and 4.01 × 106 Jones, 23.84 ms and 47.6 ms, respectively, demonstrating its potential in uncooled near-infrared photodetector applications.