Manipulating Nanowire Structures for an Enhanced Broad-Band Flexible Photothermoelectric Photodetector
Rui Wang, Zhen He, Jinlong Wang, Jiayang Liu, Jiayang Liu, Jianwei Liu, Jianwei Liu, Shu‐Hong Yu
Abstract
The photothermoelectric effect, directly converting light energy into electrical energy, shows promising prospects in self-powered broad-band optical detection, which can extend to various applications, such as sensing, optoelectronic communications, and wide-temperature-range measurements. However, the low photosensitivity, narrow-band response, and rapid performance degeneration under continuous illumination restrict its broad application. Herein, we propose a simple bottom-up strategy to manipulate nanowires (NWs) into a well-defined multilayer Te-Ag2Te-Ag NW film, resulting in a high-performance photothermoelectric photodetector with a broad-band responsivity (4.1 V/W), large detectivity (944 MHz1/2 W–1), and fast response speed (0.4–0.7 s from 365 to 1200 nm). In addition, the ultrathin structure endows this device with slow and weak transverse heat conduction, enabling a stable voltage without an obvious degeneration over 1500 s. The highly anisotropic arrangement of NWs gives this device a prominent polarization sensitivity. Prospectively, this hierarchically designed nanowire film provides a promising pathway toward engineering photodetectors with high performance.