  Transfer techniques based on two dimensional (2D) materials and devices offer
immense potential towards their industrial integration with the existing
silicon based electronics. To achieve high quality devices, there is an urgent
requirement for the etching-free, and clean transfer that retain original
semiconducting properties of layered channel materials. In parallel, transfer
of metal electrode arrays on the 2D semiconductors also attract attention
towards large-scale integration for commercial applications. Here, we
demonstrate a facile PMMA-assisted etching-free one-step approach to transfer
both 2D channels and metal electrodes without damaging the contact region. The
direct device transfer (DDT) technique enables residue-free monolayer MoS2 as
channel material towards achieving doping-free intrinsic transistors with
enhanced performances. The crystalline quality, strain relaxation, and
interfacial coupling effects are studied using Raman and photoluminescence
spectra with spatial mapping. Post device transfer, a reduced pinning effect is
observed by the effective modulation of gate tunable drain currents in MoS2
transistors at room temperature. Furthermore, the extracted Schottky barrier
heights, temperature dependence of threshold voltage shifts, hysteresis
evolution, and mobility enhancements validates the improved transistor
performances in transferred devices. The proposed DDT method can be utilized to
directly transfer array of devices of 2D materials and heterostructures
skipping various cumbersome steps in between and hence could offer high
performance reliable electronic applications.
