The present disclosure provides a method for manufacturing a flexible device having a pattern of a two-dimensional material formed thereon includes: a step of forming a two-dimensional material layer on a substrate; a step of forming a pattern of the two-dimensional material; a step of coating a flexible substrate solution on the patterned two-dimensional material layer and curing the same; and a step of removing the substrate.

A cavity structure comprises one or more seed surfaces, a first growth path for the growth of a first semiconductor structure from one of the one or more seed surfaces and a second growth path for the growth of a second semiconductor structure from one of the one or more seed surfaces. The cavity structure further comprises at least one opening for supplying precursor materials to the cavity structure. A method can include selectively growing the first semiconductor structure along the first growth path and selectively growing the second semiconductor structure along the second growth path. The first semiconductor structure has a first growth front and the second semiconductor structure has a second growth front. The method can further include merging the first and the second growth front at a border area of the first and the second semiconductor structure.

A method of growing an AlGaN semiconductor material utilizes an excess of Ga above the stoichiometric amount typically used. The excess Ga results in the formation of band structure potential fluctuations that improve the efficiency of radiative recombination and increase light generation of optoelectronic devices, in particular ultraviolet light emitting diodes, made using the method. Several improvements in UV LED design and performance are also provided for use together with the excess Ga growth method. Devices made with the method can be used for water purification, surface sterilization, communications, and data storage and retrieval.

Provided are a method of pre-treating a substrate and a method of directly forming graphene by using the method of pre-treating the substrate. In the method of pre-treating the substrate in the method of directly forming graphene, according to an embodiment, the substrate is pre-treated by using a pre-treatment gas including at least a carbon source and hydrogen. The method of directly forming graphene includes a process of pre-treating a substrate and a process of directly growing graphene on the substrate that is pre-treated. The process of pre-treating the substrate is performed according to the method of pre-treating the substrate.

Disclosed is a method of manufacturing multilayer graphene, including (a) contacting of a metal substrate with a nonmetal element, (b) reduction through heat treatment, and (c) chemical vapor deposition of a graphene precursor on the metal substrate containing the nonmetal element dissolved therein, thereby manufacturing multilayer graphene that is doped with the nonmetal element on the metal substrate. In the multilayer graphene thus manufactured, the number of graphene layers and the work function are simultaneously adjusted by controlling the concentration of doped nonmetal element in a thickness direction of graphene through interactions related to the reduction of the nonmetal element dissolved in a copper catalyst and the growth of graphene, and moreover, the stacking structure of graphene is maintained and the optoelectronic properties of multilayer graphene can be controlled by simultaneously regulating graphene growth and doping during the synthesis procedure without additional processing.

Disclosed herein is a new and improved system and method for fabricating monolithically integrated diamond semiconductor. The method may include the steps of seeding the surface of a substrate material, forming a diamond layer upon the surface of the substrate material; and forming a semiconductor layer within the diamond layer, wherein the diamond semiconductor of the semiconductor layer has n-type donor atoms and a diamond lattice, wherein the donor atoms contribute conduction electrons with mobility greater than 770 cm.sup.2/Vs to the diamond lattice at 100 kPa and 300K, and Wherein the n-type donor atoms are introduced to the lattice through ion tracks.

In some aspects, methods of forming a metal sulfide thin film are provided. According to some methods, a metal sulfide thin film is deposited on a substrate in a reaction space in a cyclical process where at least one cycle includes alternately and sequentially contacting the substrate with a first vapor-phase metal reactant and a second vapor-phase sulfur reactant. In some aspects, methods of forming a three-dimensional architecture on a substrate surface are provided. In some embodiments, the method includes forming a metal sulfide thin film on the substrate surface and forming a capping layer over the metal sulfide thin film. The substrate surface may comprise a high-mobility channel.

A template-assisted method for the synthesis of 2D nanosheets comprises growing a 2D material on the surface of a nanoparticle substrate that acts as a template for nanosheet growth. The 2D nanosheets may then be released from the template surface, e.g. via chemical intercalation and exfoliation, purified, and the templates may be reused.

A semiconductor stacked body includes: a first semiconductor layer containing a group III-V compound semiconductor and being a layer whose conductivity type is a first conductivity type; a quantum-well light-receiving layer containing a group III-V compound semiconductor; a second semiconductor layer containing a group III-V compound semiconductor; and a third semiconductor layer containing a group III-V compound semiconductor and being a layer whose conductivity type is a second conductivity type. The first semiconductor layer, the quantum-well light-receiving layer, the second semiconductor layer, and the third semiconductor layer are stacked in this order. The concentration of an impurity that generates a carrier of the second conductivity type is 110.sup.14 cm.sup.3 or more and 110.sup.17 cm.sup.3 or less in the second semiconductor layer.

A method of fabricating a semiconductor device structure includes: providing a substrate comprising a layer of compound semiconductor material; forming a seed layer of nano-crystalline diamond having a layer thickness in a range 5 to 50 nm on the layer of compound semiconductor material; and growing a layer of polycrystalline CVD diamond on the seed layer using a chemical vapour deposition (CVD) technique. An effective thermal boundary resistance (TBR.sub.eff) at an interface between the layer of compound semiconductor material and the layer of polycrystalline CVD diamond material is no more than 50 m.sup.2K/GW.