A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride. A normal line to the upper surface has an off-angle of 2.0° or less with respect to <0001> direction of the crystal of the nitride of the group 13 element.

The invention refers to a composite wavelength converter (1) for an LED (100), comprising a substrate (10) and an epitaxial film (20) formed by liquid phase epitaxy on the top and bottom of the substrate (10). Furthermore, the invention refers to a method of preparation of a composite wavelength converter (1) for an LED (100). Furthermore, the invention refers to a white LED light source comprising an LED (100) and an inventive composite wavelength converter (1) mounted on a light emitting surface of the LED (100).

The invention refers to a composite wavelength converter (1) for an LED (100), comprising a substrate (10) and an epitaxial film (20) formed by liquid phase epitaxy on the top and bottom of the substrate (10). Furthermore, the invention refers to a method of preparation of a composite wavelength converter (1) for an LED (100). Furthermore, the invention refers to a white LED light source comprising an LED (100) and an inventive composite wavelength converter (1) mounted on a light emitting surface of the LED (100).

A crystal substrate 1 includes an underlying layer 2 and a thick film 3. The underlying layer 2 is composed of a crystal of a nitride of a group 13 element and includes a first main face 2a and a second main face 2b. The thick film 3 is composed of a crystal of a nitride of a group 13 element and provided over the first main face of the underlying layer. The underlying layer 2 includes a low carrier concentration region 5 and a high carrier concentration region 4 both extending between the first main face 2a and the second main face 2b.

A crystal substrate 1 includes an underlying layer 2 and a thick film 3. The underlying layer 2 is composed of a crystal of a nitride of a group 13 element and includes a first main face 2a and a second main face 2b. The thick film 3 is composed of a crystal of a nitride of a group 13 element and provided over the first main face of the underlying layer. The underlying layer 2 includes a low carrier concentration region 5 and a high carrier concentration region 4 both extending between the first main face 2a and the second main face 2b.

The present invention provides a PZN-based large-size ternary high-performance single crystal, a growing method and a molten salt furnace. The PZN-based large-size ternary high-performance single crystal is represented by formula (1-x-y)Pb(B′.sub.1/2B″.sub.1/2)O.sub.3-yPb(Zn.sub.1/3Nb.sub.2/3)O.sub.3-xPbTiO.sub.3, wherein B′ is Mg, Fe, Sc, Ni, In, Yb, Lu and/or Ho, B″ is Nb, Ta and/or W, 0.4<x<0.6, 0.1<y<0.4, 0.1<1-x-y<0.4. The present invention adjusts the convective change of the melt through the rotation of the top seed and the bottom crucible, overcoming the problems of serious crystal inclusions and poor crystal quality during the growth process, and can adapt the change of the crystal diameter to the thermal inertia of the heat preservation system, thus effectively reducing crystal inclusions and improving the yield of the crystal.

In accordance with a method of forming a halide perovskite thin film, a first halide perovskite material is chosen from which a halide perovskite thin film is to be formed. An epitaxial substrate formed from a second halide perovskite material is also chosen. The halide perovskite thin film is epitaxially formed on the substrate from the first halide perovskite material. The substrate is chosen such that the halide perovskite thin film formed on the substrate has a selected value of at least one property. The property is selected from the group including crystal structure stability, charge carrier mobility and band gap.

In accordance with a method of forming a halide perovskite thin film, a first halide perovskite material is chosen from which a halide perovskite thin film is to be formed. An epitaxial substrate formed from a second halide perovskite material is also chosen. The halide perovskite thin film is epitaxially formed on the substrate from the first halide perovskite material. The substrate is chosen such that the halide perovskite thin film formed on the substrate has a selected value of at least one property. The property is selected from the group including crystal structure stability, charge carrier mobility and band gap.

A multi-layer thin film composite is formed by applying a thin film formed from non-single-crystalline oxide onto a substrate; applying a protection film onto the thin film; and supplying energy to the thin film through at least one of the protection film or the substrate.

A multi-layer thin film composite is formed by applying a thin film formed from non-single-crystalline oxide onto a substrate; applying a protection film onto the thin film; and supplying energy to the thin film through at least one of the protection film or the substrate.