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

•The photodetector based on exfoliated Ta2NiSe5 nanoflake exhibits a broadband photo-response from 405 nm to 4300 nm.•The Ta2NiSe5 photodetector has high responsivity ~198.1 A·W−1 at 1350 nm and ultrafast response time of ~27.4 µs.•The scanning photocurrent mapping reveals the photoconductive mechanism of Ta2NiSe5 photodetector.•Strong anisotropic ratio of the photocurrent is ~1.46.