Fig. 1. (Color online) Characterization of ZrSe₃ crystal. (a) Low-magnification transmission electron microscopy (TEM) of the quasi-1D ZrSe₃. (b) High-resolution transmission electron microscopy (HRTEM) image of the quasi-1D ZrSe₃. (c) Selected area electron diffraction (SAED) pattern of the quasi-1D ZrSe. (d) The AFM image of ZrSe₃ crystal. (e) High-resolution spectra of Zr 3d core level. (f) High-resolution spectra of Se 3d core level.

Fig. 2. (Color online) (a) Raman spectra under unpolarized and polarized laser (532 nm). (b) Counter maps of angle-resolved Raman spectra under cross configuration. (c) Counter maps of angle-resolved Raman spectra under parallel configuration. (d) Polar plots of angle-resolved and fitted peak intensities of 234.6 cm⁻¹. (e) Polar plots of angle-resolved and fitted peak intensities of 301.4 cm⁻¹.

Fig. 3. (Color online) (a) Atomic structure of ZrSe₃ crystal. (b) Band structure of layered ZrSe₃. (c) Calculated real parts and imaginary parts of the dielectric constant alonga-axis andb-axis. (d) TheR_a andR_b of optical transition |v> → |c> along the k-points path. (e, f) Partial charge density of ZrSe₃ at the state of CBM and VBM respectively.

Fig. 4. (Color online) (a) Time-resolved photoresponse of the ZrSe₃-based photodetector for a bias voltage of 5 V under 532 nm with different light power density. (b) Dependence of the photocurrent on the intensity of incident laser power. (c) The spectral responsivity and detectivity of ZrSe₃-based photodetector. (d) Evolution of the photocurrent with a polarized angle under 532 nm.

Fig. 5. (Color online) (a−c) Time-resolved photoresponse of the ZrSe₃-based photodetector for a bias voltage of 5 V under 450, 638 and 808 nm with different light power density respectively. (d–f) Evolution of the photocurrent with polarized angles under 450, 638 and 808 nm, respectively.

Table 1. Summary of the performance of a device based on quasi-1D ZrSe₃.