title: Topological Crystalline Insulator SnTe/Si Vertical Heterostructure Photodetectors for High-Performance Near-Infrared Detection.
abstract: Due to the gapless surface state and narrow bulk band gap, the light absorption of topological crystalline insulators covers a broad spectrum ranging from terahertz to infrared, revealing promising applications in new generation optoelectronic devices. To date, the photodetectors based on topological insulators generally suffer from a large dark current and a weaker photocurrent especially under the near-infrared lights, which severely limits the practical application of devices. Owing to the lower excitation energy of infrared lights, the photodetection application of topological crystalline insulators in the near-infrared region relies critically on understanding the preparation and properties of their heterostructures. Herein, we fabricate the high-quality topological crystalline insulator SnTe film/Si vertical heterostructure by a simple physical vapor deposition process. The resultant heterostructure exhibits an excellent diode characteristic, enabling the construction of high-performance near-infrared photodetectors. The built-in electric field at SnTe/Si interface enhances the absorption efficiency of near-infrared lights and greatly facilitates the separation of photogenerated carriers, making the device capable of operating as a self-driven photodetector. The as-grown SnTe film acts as the hole transport layer in heterostructure photodetectors, promoting the transport of holes to electrode and reducing electron-hole recombination effectively. These merits enable the SnTe/Si heterostructure photodetector to have a high responsivity of 2.36 AW-1, a high detectivity of 1.54 × 1014Jones, and a large bandwidth of 104Hz in the near-infrared wavelength, which makes the detector have a promising market in novel device applications.
authors.affiliation: School of Physics and Electronics, Shandong Normal University , Jinan, Shandong 250014, P. R. China.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Physics and Electronics, Shandong Normal University , Jinan, Shandong 250014, P. R. China.
authors.forename: Baoyuan
authors.initials: B
authors.lastname: Man
authors.affiliation: School for Radiological and Interdisciplinary Sciences (RAD-X) and Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, Medical College of Soochow University , Suzhou, Jiangsu 215123, P. R. China.
authors.forename: Qi
authors.identifier: http://orcid.org/0000-0002-7479-0020
authors.initials: Q
authors.lastname: Zhang
keywords: broad bandwidth; high detectivity; near-infrared photodetector; topological crystalline insulator; vertical heterostructure