Enhanced Optical Response of SnS/SnS 2 Layered Heterostructure.

The SnS/SnS 2 heterostructure was fabricated by the chemical vapor deposition method. The crystal structure properties of SnS 2 and SnS were characterized by X-ray diffraction (XRD) pattern, Raman spectroscopy, and field emission scanning electron microscopy (FESEM). The frequency dependence photoconductivity explores its carrier kinetic decay process. The SnS/SnS 2 heterostructure shows that the ratio of short time constant decay process reaches 0.729 with a time constant of 4.3 × 10 -4 s. The power-dependent photoresponsivity investigates the mechanism of electron-hole pair recombination. The results indicate that the photoresponsivity of the SnS/SnS 2 heterostructure has been increased to 7.31 × 10 -3 A/W, representing a significant enhancement of approximately 7 times that of the individual films. The results show the optical response speed has been improved by using the SnS/SnS 2 heterostructure. These results indicate an application potential of the layered SnS/SnS 2 heterostructure for photodetection. This research provides valuable insights into the preparation of the heterostructure composed of SnS and SnS 2 , and presents an approach for designing high-performance photodetection devices.