Nanoscale Bilayer Mechanical Lithography Using Water as Developer.

Sustainability has become a critical concern in the semiconductor industry as hazardous wastes released during the manufacturing process of semiconductor devices have an adverse impact on human beings and the environment. The use of hazardous solvents in existing fabrication processes also restricts the use of polymer substrates because of their low chemical resistance to such solvents. Here, we demonstrate an environmentally friendly mechanical, bilayer lithography that uses just water for development and lift-off.

Filamentary High-Resolution Electrical Probes for Nanoengineering.

Confining electric fields to a nanoscale region is challenging yet crucial for applications such as high-resolution probing of electrical properties of materials and electric-field manipulation of nanoparticles. State-of-the-art techniques involving atomic force microscopy typically have a lateral resolution limit of tens of nanometers due to limitations in the probe geometry and stray electric fields that extend over space. Engineering the probes is the most direct approach to improving this resolution limit.

Direct Laser Patterning and Phase Transformation of 2D PdSe Films for On-Demand Device Fabrication.

Heterophase homojunction formation in atomically thin 2D layers is of great importance for next-generation nanoelectronics and optoelectronics applications. Technologically challenging, controllable transformation between the semiconducting and metallic phases of transition metal chalcogenides is of particular importance. Here, we demonstrate that controlled laser irradiation can be used to directly ablate PdSe thin films using high power or trigger the local transformation of PdSe into a metallic phase PdSe using lower laser power.

Chemical Vapor Deposition Growth of Two-Dimensional Monolayer Gallium Sulfide Crystals Using Hydrogen Reduction of GaS.

Two-dimensional gallium sulfide (GaS) crystals are synthesized by a simple and efficient ambient pressure chemical vapor deposition (CVD) method using a single-source precursor of GaS. The synthesized GaS structures involve triangular monolayer domains and multilayer flakes with thickness of 1 and 15 nm, respectively. Regions of continuous films of GaS are also achieved with about 0.

Revealing Strain-Induced Effects in Ultrathin Heterostructures at the Nanoscale.

Two-dimensional materials are being increasingly studied, particularly for flexible and wearable technologies because of their inherent thickness and flexibility. Crucially, one aspect where our understanding is still limited is on the effect of mechanical strain, not on individual sheets of materials, but when stacked together as heterostructures in devices. In this paper, we demonstrate the use of Kelvin probe microscopy in capturing the influence of uniaxial tensile strain on the band-structures of graphene and WS (mono- and multilayered) based heterostructures at high resolution.

Design parameters for voltage-controllable directed assembly of single nanoparticles.

Techniques to reliably pick-and-place single nanoparticles into functional assemblies are required to incorporate exotic nanoparticles into standard electronic circuits. In this paper we explore the use of electric fields to drive and direct the assembly process, which has the advantage of being able to control the nano-assembly process at the single nanoparticle level. To achieve this, we design an electrostatic gating system, thus enabling a voltage-controllable nanoparticle picking technique.