Summary: | 博士 === 國立交通大學 === 光電工程研究所 === 106 === In this study, we successfully demonstrated the thermally strained band gap engineering of molybdenum disulfide (MoS2) bilayers by different thermal expansion coefficients of patterned sapphire structures (PSSs). In particular, a blue shift in the band gap of the MoS2 bilayers can be tunable, displaying an extraordinary capability to drive electrons toward electrode under the smaller driven bias and the results were confirmed by the simulation. A model to explain the thermal strain in the MoS2 bilayers enables us to predict the band gap-shifted behaviors on PSSs with different angles.
From electrical measurement, we found that cone-patterned sapphire substrate (CPSS) is able to generate more photocurrent under the blue light illumination, on the other hand the pyramid-patterned sapphire substrate (PPSS) has an outstanding performance under the green and red light illumination. Based on the 3D model simulations, the electric field distributions for the MoS2 pasted on different substrates showed that the superior sensitivity of MoS2-based photodetector can be greatly improved by the light scattering effect. Finally, we use those advantages of MoS2-based three-dimensional devices to develop a novel light-enhanced NO gas sensor with highly response at room temperature operating.
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