Tuning the Layered Thickness of MoTe₂ Thin Film for Dye-Sensitized Solar Cells, UV and Visible Spectrum Photodetectors, and Hydrogen Evolution Reaction

Atomically thick van der Waals (VdW)-bonded layered transition metal dichalcogenide (TMD) structures have influenced the investigation of novel phenomena for modern electronics and energy devices immensely. Herein, the fabrication of atomically thick tunable mollybednum ditelluride thin films on substrates through a chemical bath methodology is shown for the first time. The proposed methodology can be used to fine tune the atomic layer thickness of MoTe₂ with highly modified surface characteristics, which is a greatly interesting feature for multifunctional nanodevice fabrication. Microscopic images confirm the atomic layer thickness-tuned MoTe₂. Furthermore, a photodetector assembled using few-layer-thick (S4) MoTe₂ shows a high photoresponsivity of 3.21 A W⁻¹ under ultraviolet light and an excellent detectivity of 5.4 × 10¹¹ Jones, and a dye-sensitized solar cell constructed using a photocathode made from S4 MoTe₂ atomic layers shows a high power conversion efficiency of 8.44%, which is much greater than that of many other layered TMD structures. In addition, synthesized S4 MoTe₂ atomic layers exhibit excellent hydrogen evolution characteristics in alkaline and acidic media. The resulting outcomes obviously establish the advantages of developed layered thick MoTe₂ to produce the outstanding interface characteristics between the vdW-bonded atomic layers to achieve outstanding energy and semiconductor devices.