Direct Transfer of Monolayer MoS2 Device Arrays for Potential Applications in Flexible Electronics

Transfer techniques of two-dimensional (2D) materials and devices offer nanoscale integration with the existing silicon-based technology and flexible electronics. To date, the chemical etching technique is being widely used for the transfer of 2D materials, and there has been constant effort in improving the method to achieve an etching-free and clean transfer of 2D materials without affecting the device performances. Herein, we demonstrate a poly(methyl methacrylate) (PMMA)-assisted etching-free one-step approach to transfer device arrays consisting of monolayer MoS 2 and metal electrodes to different substrates (i.e., SiO 2 /Si, flexible). The crystalline quality, strain relaxation, and interfacial coupling effects of the transferred devices are analyzed using Raman and photoluminescence spectroscopy. The room-temperature gate-tunable drain current measurements of the transferred devices on the SiO 2 /Si substrate show a reduced Fermi-level pinning effect. Furthermore, the observation from temperature-dependent threshold voltage shifts, mobilities, and hysteresis evolution indicates an improved transistor performance in the transferred device. The proposed one-step transfer method could be useful to transfer a large array of 2D material devices on arbitrary substrates for future flexible optoelectronic applications.