High-Responsivity, High-Detectivity, Ultrafast Topological Insulator Bi2Se3/Silicon Heterostructure Broadband Photodetectors

• Published in: ACS nano Vol. 10; no. 5; pp. 5113 - 5122
• Main Authors: Zhang, Hongbin, Zhang, Xiujuan, Liu, Chang, Lee, Shuit-Tong, Jie, Jiansheng
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 24.05.2016
• Subjects: topological insulator; high responsivity; silicon; fast photoresponse; heterostructure photodetector
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.6b00272

As an exotic state of quantum matter, topological insulators have promising applications in new-generation electronic and optoelectronic devices. The realization of these applications relies critically on the preparation and properties understanding of high-quality topological insulators, which however are mainly fabricated by high-cost methods like molecular beam epitaxy. We here report the successful preparation of high-quality topological insulator Bi2Se3/Si heterostructure having an atomically abrupt interface by van der Waals epitaxy growth of Bi2Se3 films on Si wafer. A simple, low-cost physical vapor deposition (PVD) method was employed to achieve the growth of the Bi2Se3 films. The Bi2Se3/Si heterostructure exhibited excellent diode characteristics with a pronounced photoresponse under light illumination. The built-in potential at the Bi2Se3/Si interface greatly facilitated the separation and transport of photogenerated carriers, enabling the photodetector to have a high light responsivity of 24.28 A W–1, a high detectivity of 4.39 × 1012 Jones (Jones = cm Hz1/2 W–1), and a fast response speed of aproximately microseconds. These device parameters represent the highest values for topological insulator-based photodetectors. Additionally, the photodetector possessed broadband detection ranging from ultraviolet to optical telecommunication wavelengths. Given the simple device architecture and compatibility with silicon technology, the topological insulator Bi2Se3/Si heterostructure holds great promise for high-performance electronic and optoelectronic applications.