Strongly Anisotropic Quasi‐1D BaTiS3 Chalcogenide Perovskite for Near‐Infrared Polarized Photodetection

Abstract

AbstractOne‐dimensional (1D) crystal‐structural materials have attracted extensive attention for polarization detection because of the strong anisotropy. Barium titanium sulfide (BaTiS3), a quasi‐1D chalcogenide perovskite, demonstrates a great potential for polarization detection stemming from the giant optical anisotropy. Whereas, the photoelectric properties of BaTiS3 and its direct application in polarized photodetector are less studied. Herein, quasi‐1D BaTiS3 is introduced in polarized photodetection for the first time. The needle‐like BaTiS3 single crystals are successfully prepared by a modified chemical vapor transport process. The BaTiS3 single crystal demonstrates a narrow bandgap of 0.8 eV, an n‐type intrinsic conductivity, and a more than 300 cm2 V−1 s−1 mobility along the c‐axis. Then, an Ag/BaTiS3/Ag photoconductive detector is fabricated. It shows a broad detection wavelength ranging from visual light to 1550 nm and high responsivity of ≈1.22 A W−1. Moreover, an orthogonal reverse property of polarization photocurrent is observed under the excitation energy of 1.70 eV and 1.96 eV. These comprehensive characteristics can promote the application of the quasi‐1D BaTiS3 in near‐infrared polarized photodetection.