Methods of controlling island size and density on an OMVPE growth film may comprise adding a surfactant at a critical concentration level, allowing a growth phase for a first period of time, and ending the growth phase when desired island size and density are achieved. For example, the island size and density of an OMVPE grown InGaN thin film may be controlled by adding an antimony surfactant at a critical concentration level.

Techniques for processing materials in supercritical fluids including processing in a capsule disposed within a high-pressure apparatus enclosure are disclosed. The disclosed techniques are useful for growing crystals of GaN, AlN, InN, and their alloys, including InGaN, AlGaN, and AlInGaN for the manufacture of bulk or patterned substrates, which in turn can be used to make optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation devices, photodetectors, integrated circuits, and transistors.

Techniques for processing materials in supercritical fluids including processing in a capsule disposed within a high-pressure apparatus enclosure are disclosed. The disclosed techniques are useful for growing crystals of GaN, AlN, InN, and their alloys, including InGaN, AlGaN, and AlInGaN for the manufacture of bulk or patterned substrates, which in turn can be used to make optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation devices, photodetectors, integrated circuits, and transistors.

A method for producing a waveguide including a germanium-based core and a cladding is provided, the method including a step of “low temperature” depositing of a shell after forming the core by engraving, such that the deposition temperature is less than 780° C., followed by a step of “high temperature” depositing of a thick encapsulation layer. The shell and the encapsulation layer at least partially form the cladding of the waveguide. Optionally, a step of annealing under hydrogen at a “low temperature”, less than 750° C., precedes the deposition of the shell. These “low temperature” annealing and depositing steps advantageously make it possible to avoid a post-engraving alteration of the free surfaces of the core during the forming of the cladding which is less germanium-rich.

A method for producing a waveguide including a germanium-based core and a cladding is provided, the method including a step of “low temperature” depositing of a shell after forming the core by engraving, such that the deposition temperature is less than 780° C., followed by a step of “high temperature” depositing of a thick encapsulation layer. The shell and the encapsulation layer at least partially form the cladding of the waveguide. Optionally, a step of annealing under hydrogen at a “low temperature”, less than 750° C., precedes the deposition of the shell. These “low temperature” annealing and depositing steps advantageously make it possible to avoid a post-engraving alteration of the free surfaces of the core during the forming of the cladding which is less germanium-rich.

A method is disclosed for making semiconductor films from a eutectic alloy comprising a metal and a semiconductor. Through heterogeneous nucleation said film is deposited at a deposition temperature on relatively inexpensive buffered substrates, such as glass. Specifically said film is vapor deposited at a fixed temperature in said deposition temperature where said deposition temperature is above a eutectic temperature of said eutectic alloy and below a temperature at which the substrate softens. Such films could have widespread application in photovoltaic and display technologies.

A method is disclosed for making semiconductor films from a eutectic alloy comprising a metal and a semiconductor. Through heterogeneous nucleation said film is deposited at a deposition temperature on relatively inexpensive buffered substrates, such as glass. Specifically said film is vapor deposited at a fixed temperature in said deposition temperature where said deposition temperature is above a eutectic temperature of said eutectic alloy and below a temperature at which the substrate softens. Such films could have widespread application in photovoltaic and display technologies.

Disclosed is a process of surface treatment of a substrate. The method of treating a surface of a substrate comprises preparing the substrate, and performing an etching process with respect to a surface of the substrate. The etching process comprises a step of introducing etching gas to the surface of the substrate, and the etching gas comprises a halogen compound and a silane compound.

According to an embodiment, a radiation detector comprises a photoelectric conversion substrate and a scintillator layer. The photoelectric conversion substrate converts light into an electrical signal. The scintillator layer contacts the photoelectric conversion substrate and converts radiation incident from the outside into light. The scintillator layer is a fluorescer of CsI containing Tl as an activator. The CsI is a halide. The concentration of the activator inside the fluorescer is 1.6 mass %±0.4 mass %. The concentration of the activator inside the fluorescer in an in-plane direction of the scintillator layer has the relationship of central portion>peripheral portion. The central portion is a central region of a formation region of the scintillator layer. The peripheral portion is an outer circumferential region of the formation region of the scintillator layer.

Described herein is a method for growing indium nitride (InN) materials by growing hexagonal and/or cubic InN using a pulsed growth method at a temperature lower than 300° C. Also described is a material comprising InN in a face-centered cubic lattice crystalline structure having an NaCl type phase.