Abstrakt
The research on graphene has attracted much attention since its first successful preparation in 2004. It possesses many unique properties, such as an extreme stiffness and strength, high electron mobility, ballistic transport even at room temperature, superior thermal conductivity and many others.
The affection for graphene was followed swiftly by a keen interest in other two dimensional materials like transition metal dichalcogenides. As has been predicted and in part proven experimentally, the electronic properties of these materials can be modified by various means.
The most common ones include covalent or non-covalent chemistry, electrochemical, gate or atomic doping, or quantum confinement. None of these methods has proven universal enough in terms of the devices' characteristics or scalability.
However, another approach is known mechanical strain/stress, but experiments in that direction are scarce, in spite of their high promises. The primary challenge consists in the understanding of the mechanical properties of 2D materials and in the ability to quantify the lattice deformation.
Several techniques can be then used to apply strain to the specimens and thus to induce changes in their electronic structure. We will review their basic concepts and some of the examples so far documented experimentally and/or theoretically.