We exfoliated bulk GaGeTe crystals down to ultrathin flakes using the scotch tape method and fabricated field effect transistors (FETs). The GaGeTe FETs display a p-type behavior with drain current modulation on the order of 103, hole mobility of 0.45 cm2 V−1 s−1, and photoresponsivity of 3.6 A W−1 at room temperature. These findings suggest that the layered GaGeTe is a promising 2D semiconductor for fabricating devices, such as transistors and photodetectors.

This work presents a systematic study of phonon modes in a ZrGeTe4 layered semiconductor by Raman spectroscopy. Ten Raman characteristic peaks were detected and determined by density functional perturbation theory calculations. All Raman mode shifts exhibit a linear temperature dependence. The first-order temperature coefficients (χ) of the ZrGeTe4 Raman mode are in the range of −0.0058 cm−1/K to −0.01831 cm−1/K. Moreover, we demonstrate the strong anisotropic Raman response for linearly polarized excitation. The intensities of the observed Raman modes show periodic variation with the sample rotating under the angle-dependent and polarized Raman spectroscopy measurements, showing the high anisotropy of ZrGeTe4. Our results prove that ZrGeTe4 is a highly in-plane anisotropic 2D semiconductor, suggesting its potential application in nanoelectronic devices.

Converting solar energy into sustainable hydrogen fuel by photoelectrochemical (PEC) water splitting is a promising technology to solve increasingly serious global energy supply and environmental issues. However, the PEC performance based on TiO2 nanomaterials is hindered by the limited sunlight-harvesting ability and its high recombination rate of photogenerated charge carriers. In this work, layered SnS2 absorbers and CoOx nanoparticles decorated two-dimensional (2D) TiO2 nanosheet array photoelectrode have been rationally designed and successfully synthesized, which remarkably enhanced the PEC performance for water splitting. As the result, photoconversion efficiency of TiO2/SnS2/CoOx and TiO2/SnS2 hybrid photoanodes increases by 3.6 and 2.0 times under simulated sunlight illumination, compared with the bare TiO2 nanosheet arrays photoanode. Furthermore, the TiO2/SnS2/CoOx photoanode also presented higher PEC stability owing to CoOx catalyst served as efficient water oxidation catalyst as well as an effective protectant for preventing absorber photocorrosion.

Infrared photodetectors have attracted great interest due to their wide range of applications. (TaSe4)2I nanowires were prepared by the scotch-tape mechanical exfoliation method, and optoelectronic properties are systematically investigated. The (TaSe4)2I photodetector shows superior performance under the leading role of the photo-bolometric effect. Remarkably, the prefabricated photodetector recorded a superior responsivity of 0.792 A W−1 and a high external quantum efficiency of 100.259% under the condition of near-infrared light. These excellent properties suggest that (TaSe4)2I is a highly competitive candidate for high-performance near-infrared photodetectors.

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