Single‐crystal growth: From new borates to industrial semiconductors

Abstract

In this paper, we present our progresses on single‐crystal growth of a variety of compounds from new borates to industrial semiconductors, reflecting our efforts in new compounds exploration, structure analysis, property characterization, flux growth, and vapor growth of industrial semiconductors. Typical examples are selected with each serving to show one theme. YBa3B9O18 and ErBa3B9O18, two members of a newly discovered series RBa3B9O18 (R = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) are found to be potential scintillation materials and laser hosts. KZnB3O6, the first borate with edge‐sharing BO4 tetrahedra obtained under ambient conditions, shows a very interesting selective ion exchange. The study of a well‐known crystal YVO4 reveals that the negative refraction (NR) is an intrinsic property of all uniaxial crystals. For technically important crystals, our emphases are placed on the study of growth methods. GaN is successfully realized to grow under very facile conditions based on a flux method developed from combining the phase relation calculation and experiments. Achievements on growth of 2–4 inch quality SiC wafers, both semi‐insulating and conducting, through improved physical vapor transport (PVT) method are also reported. A brief summary and our perspectives on crystal growth are given at the end. 2–4‐inch n‐type 4H‐SiC wafers grown by a PVT method.

Giant magneto-optical Kerr enhancement from films on SiC due to the optical properties of the substrate

“…In this paper we demonstrate MOKE enhancement in three samples: 1) Multilayer graphene epitaxially grown on a c-face 4H-SiC substrate, which was produced by etching the 4H-SiC substrate in hydrogen and then annealing at 1600˚C while maintaining a 10 -4 mbar vacuum in a chemical vapor deposition system [31]; 2) Iron films of 3 and 10 nm thicknesses sputtered onto a semi-insulating 4H-SiC substrate, with a sputtering power and pressure of 50 W and 30 mTorr, respectively; and 3) Al-doped SiC prepared in an inductively heated furnace by using a physical vapor transport method [32].…”

Experimental electron density distribution of KZnB3O6 constructed by maximum-entropy method

“…In the past decades, borate crystals have garnered significant attention due to their diverse applications in nonlinear optical materials, fluorescent materials, and laser crystals (Xu et al, 1995;Wang and Chen, 2010). Boron, with its sp 2 and sp 3 hybridized chemical bonds, can form either BO 3 triangles (Wu et al, 2006) or BO 4 tetrahedra by binding to oxygen atoms (He et al, 2005).…”

Synchrotron X-ray diffraction characterization of the inheritance of GaN homoepitaxial thin films grown on selective growth substrates

“…However, because there are some difficulties in the growth of single crystals of bulk GaN, researchers have had to grow GaN films on other foreign substrates, such as sapphire, gallium arsenide, silicon, and silicon carbide. 8 There are well-known significant differences in the lattice parameters and coefficients of thermal expansion between GaN and other substrates that could inevitably lead to lattice strains and defects (e.g., grain boundaries and threading dislocations) in the film, decreasing the device performance. For several decades, many research institutions and laboratories have devoted many resources to improve the wafer size and crystal quality of the bulk GaN [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] and homoepitaxial layers.…”