Clean transfer of two-dimensional materials using UV-ozone treated polydimethylsiloxane

The clean and reliable transfer of two-dimensional (2D) materials is critical for preserving their intrinsic properties and enabling high-performance device applications. This study presents a method utilizing UV-ozone treated polydimethylsiloxane (UV-PDMS) as a transfer medium to achieve residue-free 2D materials. The UV-PDMS transfer method increases surface rigidity, reduces surface polymeric residues, and ensures intimate contact between 2D materials and target substrates. This is translated into cleaner samples as confirmed by atomic force microscopy (AFM), photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Field-effect transistors (FETs) based on monolayer MoS 2 fabricated with UV-PDMS transferred method exhibit lower subthreshold swing, reduced hysteresis, and higher carrier mobility compared to devices fabricated with PDMS transfer. Additionally, vertical solar cells based on multilayer WSe 2 prepared with UV-PDMS method demonstrate enhanced fill factor and power conversion efficiency.