Disclosed is a nanocrystalline boron nitride film having a relatively low dielectric constant and excellent mechanical properties. The nanocrystalline boron nitride film includes a crystalline boron nitride compound, and has a dielectric constant within a range of 2.5 to 5.5 at a 100 kHz operating frequency.

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.

Organic-inorganic perovskite nanoparticle compositions are described herein. In some embodiments, a nanoparticle composition comprises a layer of organic-inorganic perovskite nanocrystals, the organic-inorganic perovskite nanocrystals comprising surfaces associated with ligands of size unable to incorporate into octahedral corner sites of the perovskite crystal structure.

Organic-inorganic perovskite nanoparticle compositions are described herein. In some embodiments, a nanoparticle composition comprises a layer of organic-inorganic perovskite nanocrystals, the organic-inorganic perovskite nanocrystals comprising surfaces associated with ligands of size unable to incorporate into octahedral corner sites of the perovskite crystal structure.

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°).

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°).

Various single crystals are disclosed including sapphire as well as methods of forming the same. A method of forming a crystalline structure is disclosed as well. The method can include providing a melt in a crucible having a die. The die can include a ventilation opening. The method can further include growing the crystalline structure from the die using an enclosed seed. The single crystals can have desirable geometric properties, including a length greater than a diameter greater than a thickness.

Various single crystals are disclosed including sapphire as well as methods of forming the same. A method of forming a crystalline structure is disclosed as well. The method can include providing a melt in a crucible having a die. The die can include a ventilation opening. The method can further include growing the crystalline structure from the die using an enclosed seed. The single crystals can have desirable geometric properties, including a length greater than a diameter greater than a thickness.

A large grain quasi-single-crystal film and a manufacturing method thereof are provided. The metal film having the <111> preferred orientation on its surface is subjected to mechanical tensile force to make the arrangement of crystal grains more ordered. The metal film is grown into a film with large crystal grains having an average diameter of over 500 microns by annealing at a temperature below the recrystallization temperature, thereby obtaining a large grain quasi-single-crystal film having the preferred directions of three axes. The large grain quasi-single-crystal film has a <110> preferred orientation along the tensile direction and a <211> preferred orientation along the direction vertical to the tensile force, and maintains a <111> preferred orientation on its top surface. The present invention can be used to produce highly anisotropic large-area quasi-single-crystal films, and can also be applied to grow 2-dimensional materials or develop anisotropic structures.

A manufacturing method includes: (1) providing M-M′ nanowires, wherein M′ is at least one sacrificial metal different from M; and (2) subjecting the M-M′ nanowires to electrochemical de-alloying to form jagged M nanowires.