Fig. 1. (a) Diagram of CVT; (b) SnSe₂ single crystal; (c) Diagram of graph transfer method.

Fig. 2. (a) XRD spectrum and (b) TEM image of SnSe₂.

Fig. 3. XPS spectrum of SnSe₂.

Fig. 4. (a) AFM of sample; (b) Optical micro-image of sample.

Fig. 5. Raman spectrum of sample.

Fig. 6. (a) Output characteristic of the field effect transistor based on two-dimensional SnSe₂; (b) Transfer characteristic of the field effect transistor.

Fig. 7. I-V curve: (a) 405 nm; (b) 532 nm; (c) 650 nm. Photocurrent curve: (d) 405 nm; (e) 532 nm; (f) 650 nm. Rising edge and falling edge: (g) 405 nm; (h) 532 nm; (i) 650 nm.

Fig. 8. Light response curve: (a) 405 nm; (b) 532 nm; (c) 650 nm. Responsivity and detectivity scatter plot of device: (d) 405 nm; (e) 532 nm; (f)650 nm.