1 research outputs found
Thermally Strained Band Gap Engineering of Transition-Metal Dichalcogenide Bilayers with Enhanced Light–Matter Interaction toward Excellent Photodetectors
Integration
of strain engineering of two-dimensional (2D) materials
in order to enhance device performance is still a challenge. Here,
we successfully demonstrated the thermally strained band gap engineering
of transition-metal dichalcogenide bilayers by different thermal expansion
coefficients between 2D materials and patterned sapphire structures,
where MoS<sub>2</sub> bilayers were chosen as the demonstrated materials.
In particular, a blue shift in the band gap of the MoS<sub>2</sub> bilayers can be tunable, displaying an extraordinary capability
to drive electrons toward the electrode under the smaller driven bias,
and the results were confirmed by simulation. A model to explain the
thermal strain in the MoS<sub>2</sub> bilayers during the synthesis
was proposed, which enables us to precisely predict the band gap-shifted
behaviors on patterned sapphire structures with different angles.
Furthermore, photodetectors with enhancement of 286% and 897% based
on the strained MoS<sub>2</sub> on cone- and pyramid-patterned sapphire
substrates were demonstrated, respectively