Ultra-broadband photodetection based on two-dimensional layered Ta2NiSe5 with strong anisotropy and high responsivity

Broadband photodetectors have attracted substantial attention in recent years. The ternary chalcogenide Ta2NiSe5 is a layered material with a direct narrow-band gap (E-g similar to 0.33 eV) which possesses greatly potential to broadband photodetectors. Here, high-quality bulk Ta2NiSe5 was synthesized by Chemical Vapor Transport (CVT) method. We demonstrate a photodetector based on exfoliated Ta2NiSe5 nanoflake, which exhibits a broadband photo-response from 405 nm to 4300 nm. Meanwhile, its main characteristics are superior to other typical 2D materials: high responsivity similar to 198.1 A W-1 at 1350 nm and ultrafast response time of similar to 27.4 ms. Long-time photocurrent reproducibility shows that the photodetector has excellent stability under atmosphere. Furthermore, the scanning photocurrent mapping reveals the photoconductive mechanism of Ta2NiSe5 photodetector. In addition, the anisotropic ratio of the photocurrent is similar to 1.46. The broadband photodetection, high responsivity, anisotropic and environmental stability achieved simultaneously in Ta2NiSe5 photodetector, which are promising for neotype electronics and optoelectronics field. (C) 2021 The Authors. Published by Elsevier Ltd.

Automated summary

High-quality Ta2NiSe5 was synthesized by CVT, and a broadband photodetector with fast response, high responsivity, and excellent stability was fabricated. The device showed promise in the field of neotype electronics and optoelectronics.