A GaN single crystal having a gallium polar surface which is a main surface on one side and a nitrogen polar surface which is a main surface on the opposite side, wherein on the gallium polar surface is found at least one square area, an outer periphery of which is constituted by four sides of 2 mm or more in length, and, when the at least one square area is divided into a plurality of sub-areas each of which is a 100 μm×100 μm square, pit-free areas account for 80% or more of the plurality of sub-areas.

The present disclosure generally relates to compositions comprising substrate-free 2D tellurene crystals, and the method of making and using the substrate-free 2D tellurene crystals. The 2D tellurene crystals of the present disclosure are characterized by an X-ray diffraction pattern (CuKα radiation, λ=1.54056 A) comprising a peak at 23.79 (2θ±0.1°) and optionally one or more peaks selected from the group consisting of 41.26, 47.79, 50.41, and 64.43 (2θ±0.1°).

Embodiments of the present disclosure include techniques related to techniques for processing materials for manufacture of group-III metal nitride and gallium based substrates. More specifically, embodiments of the disclosure include techniques for growing large area substrates using a combination of processing techniques. Merely by way of example, the disclosure can be applied to growing crystals of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, and others for manufacture of bulk or patterned substrates. Such bulk or patterned substrates can be used for a variety of applications including optoelectronic and electronic devices, lasers, light emitting diodes, solar cells, photo electrochemical water splitting and hydrogen generation, photodetectors, integrated circuits, and transistors, and others.

The present invention relates to a method for reducing lateral growth as well as growth of the bottom surface of crystals in a crystal growing process, wherein before the crystal seed undergoes a growing process the method includes a step of wrapping the crystal seed with metal foil so that all the side surfaces as well as the bottom surface of the crystal seed are surrounded by the foil.

Materials containing picocrystalline quantum dots that form artificial atoms are disclosed. The picocrystalline quantum dots (in the form of born icosahedra with a nearly-symmetrical nuclear configuration) can replace corner silicon atoms in a structure that demonstrates both short range and long-range order as determined by x-ray diffraction of actual samples. A novel class of boron-rich compositions that self-assemble from boron, silicon, hydrogen and, optionally, oxygen is also disclosed. The preferred stoichiometric range for the compositions is (B.sub.12H.sub.w).sub.xSi.sub.yO.sub.z with 3≤w≤5, 2≤x≤4, 2≤y≤5 and 0≤z≤3. By varying oxygen content and the presence or absence of a significant impurity such as gold, unique electrical devices can be constructed that improve upon and are compatible with current semiconductor technology.

An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10.sup.−5 Å or less is observed.

High quality ammonothermal group III metal nitride crystals having a pattern of locally-approximately-linear arrays of threading dislocations, methods of manufacturing high quality ammonothermal group III metal nitride crystals, and methods of using such crystals are disclosed. The crystals are useful for seed bulk crystal growth and as substrates for light emitting diodes, laser diodes, transistors, photodetectors, solar cells, and for photoelectrochemical water splitting for hydrogen generation devices.

Embodiments of the disclosure an apparatus for solvothermal crystal growth, comprising: a pressure vessel having a cylindrical shape and a vertical orientation; a cylindrical heater having an upper zone and a lower zone that can be independently controlled; at least one end heater; and an inward-facing surface of a baffle placed within 100 millimeters of a bottom end or top end surface of the growth chamber. The end heater is configured to enable: a variation in the temperature distribution along a first surface to be less than about 10° C., and a variation in the temperature distribution along a second surface to be less than about 20° C., during a crystal growth process. The first surface has a cylindrical shape and is positioned within the pressure vessel, and the second surface comprises an inner diameter of the growth chamber, and the temperature distribution along the second surface is created within an axial distance of at least 100 millimeters of an end of the growth chamber proximate to the first surface.

Various articles and devices can be manufactured to take advantage of a what is believed to be a novel thermodynamic cycle in which spontaneity is due to an intrinsic entropy equilibration. The novel thermodynamic cycle exploits the quantum phase transition between quantum thermalization and quantum localization. Preferred devices include a phonovoltaic cell, a rectifier and a conductor for use in an integrated circuit.

Materials containing picocrystalline quantum dots that form artificial atoms are disclosed. The picocrystalline quantum dots (in the form of born icosahedra with a nearly-symmetrical nuclear configuration) can replace corner silicon atoms in a structure that demonstrates both short range and long-range order as determined by x-ray diffraction of actual samples. A novel class of boron-rich compositions that self-assemble from boron, silicon, hydrogen and, optionally, oxygen is also disclosed. The preferred stoichiometric range for the compositions is (B.sub.12H.sub.w).sub.xSi.sub.yO.sub.z with 3≤w≤5, 2≤x≤4, 2≤y≤5 and 0≤z≤3. By varying oxygen content and the presence or absence of a significant impurity such as gold, unique electrical devices can be constructed that improve upon and are compatible with current semiconductor technology.