Direct Polarimetric Image Sensor and Wide Spectral Response Based on Quasi‐1D Sb2S3 Nanowire

Abstract

AbstractPolarized photodetectors with wide spectral detection and ultra‐fast photoresponses based on anisotropic semiconductors have potential applications in military and civilian fields and have been widely studied in recent years. The dual advantages of low‐symmetry crystal structure and special electronic band‐structure make Sb2S3 the perfect choice for polarized photodetection. In this work, the optical, vibrational, and optoelectronic anisotropy of the high‐quality orthorhombic Sb2S3 nanowires are systematically investigated by experimental and theoretical studies. The metal‐semiconductor‐metal photodetectors based on a single Sb2S3 nanowire exhibit good polarization sensitivity in a broadband range from ultraviolet to near‐infrared (360 to 1550 nm) and the obtained maximum dichroic ratio is 2.54 at 638 nm. The polarization‐sensitive photocurrent mapping results show that the photocurrent is mainly derived from the Schottky junction at the interface between Au and Sb2S3. The effective separation of the photo‐generated carriers near the Schottky junction gives a photodetector response time of 470 µs. The direct polarimetric imaging demonstrates that the gray value of the image obtained by the imaging system is sensitive to the object's polarized direction. This natural sensitivity of the Sb2S3‐based photodetector to polarized objects makes it possible to image polarized objects directly as an image sensor.