Strain Engineering of MoS2 by Tuning the Transfer Process

Strain engineering is a powerful technique to enhance the carrier mobility of silicon in semiconductor technology. Similarly, introducing tensile strain can increase the mobility of MoS₂ and other transition metal dichalcogenides. Although bending a flexible substrate is a simple and effective method to introduce tensile strain into MoS₂, the application of tensile strain to MoS₂ on a rigid substrate, such as surface-oxidized silicon (SiO₂/Si), is highly desirable. In this study, tensile and compressive strains were introduced into monolayer MoS₂ on SiO₂/Si by adjusting the transfer process. By increasing the thermal treatment temperature during the transfer process, the biaxial strain of approximately 0.5% was introduced into MoS₂, as confirmed by Raman spectroscopy. Consequently, we found that the carrier mobility of MoS₂ with a thermal treatment temperature of 130 °C was higher than MoS₂ with a 50 °C thermal treatment. Therefore, tuning the transfer process can control the properties of two-dimensional (2D) materials and achieve performance-controlled 2D material-based devices.