Peel-and-Stick Integration of Atomically Thin Nonlayered PtS Semiconductors for Multidimensionally Stretchable Electronic Devices

van der Waals (vdW) crystals with unparalleled electromechanical properties have been explored for transformative devices. Currently, the availability of 2D vdW crystals is rather limited in nature as they are only obtained from certain mother crystals with intrinsically possessed layered crystallinity and anisotropic molecular bonding. Recent efforts to transform conventionally non-vdW three-dimensional (3D) crystals into ultrathin 2D-like structures have seen rapid developments to explore device building blocks of unique form factors. Herein, we explore a ???peel-and-stick??? approach, where a nonlayered 3D platinum sulfide (PtS) crystal, traditionally known as a cooperate mineral material, is transformed into a freestanding 2D-like membrane for electromechanical applications. The ultrathin (???10 nm) 3D PtS films grown on large-area (>cm2) silicon dioxide/silicon (SiO2/Si) wafers are precisely ???peeled??? inside water retaining desired geometries via a capillary-force-driven surface wettability control. Subsequently, they are ???sticked??? on strain-engineered patterned substrates presenting prominent semiconducting properties, i.e., p-type transport with an optical band gap of ???1.24 eV. A variety of mechanically deformable strain-invariant electronic devices have been demonstrated by this peel-and-stick method, including biaxially stretchable photodetectors and respiratory sensing face masks. This study offers new opportunities of 2D-like nonlayered semiconducting crystals for emerging mechanically reconfigurable and stretchable device technologies.

Automated summary

Van der Waals (vdW) crystals with exceptional electromechanical properties are being explored for transformative devices. However, the availability of 2D vdW crystals is limited in nature, as they are typically obtained from specific mother crystals with layered crystallinity. This study presents a novel "peel-and-stick" approach to transform a nonlayered 3D platinum sulfide (PtS) crystal into a freestanding 2D-like membrane for electromechanical applications. The ultrathin PtS films are grown on large-area silicon dioxide/silicon wafers and precisely peeled inside water to achieve desired geometries. They are then sticked onto strain-engineered substrates, demonstrating excellent semiconductor properties. Various mechanically deformable electronic devices, such as stretchable photodetectors and respiratory sensing face masks, have been successfully fabricated using this method. This study opens up new possibilities for the application of nonlayered semiconducting crystals in mechanically reconfigurable and stretchable devices.