Figure 2: Thermal current measurement of SnS2 by laser scanning photoinduced TE current imaging. | Nature Communications

Figure 2: Thermal current measurement of SnS2 by laser scanning photoinduced TE current imaging.

From: Thermoelectric materials by using two-dimensional materials with negative correlation between electrical and thermal conductivity

Figure 2

Devices are 16 nm thick. (a) Schematic of the photo-TE measurement setup with a laser wavelength of λ=405 nm and laser power of 45 μW, where we simultaneously collect images of photo-TE current and optical reflectance as a function of the laser position. (b) Scanning photo-TE current imaging (0 V source/drain bias), which demonstrates largely thermocurrent-dominated profile in the source (S)/drain (D) electrode regions. The outline of the electrodes (yellow solid lines) and the SnS2 nanosheet (red dashed line) are indicated from reflection image of e. Scale bar, 3 μm. (c) AFM image of SnS2. Scale bar, 5 μm. (d) Thickness measurement along the red line in the AFM image. (e) Reflection image. Scale bar, 3 μm. (f) Numerical derivative of the reflectance data along the blue dashed line allows for clear indication of S/D and SnS2 boundaries. (g) Ultraviolet–visible absorption spectroscopy. The absorption edge of SnS2 films showing the bandgap at 2.59 eV, extrapolated from the x intercept of the linear portion of our data (red line).

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