The disclosure provides a method for growing a gallium oxide single crystal by casting and a semiconductor device containing the gallium oxide single crystal. The method includes: 1) heating a solid gallium oxide to complete melting, cooling to a melting point of the gallium oxide, and maintaining a melt state for at least 30 min; and 2) conducting gradient cooling on a gallium oxide melt obtained in step 1) until a solid gallium oxide single crystal is obtained. The gradient cooling is to cool the gallium oxide melt obtained in step 1) to a first temperature according to a first gradient, and then continue cooling to a room temperature according to a second gradient to obtain the gallium oxide single crystal. In step 1), since the solid gallium oxide is heated to the first temperature, oxygen with a volume fraction of at least 2% is present in a growth atmosphere.

The present invention comprises directionally solidified multicrystalline silicon ingots, a silicon masteralloy for increasing the efficiency of solar cells made from wafers cut from the silicon ingots, method for increasing the yield when producing multicrystalline silicon ingots from a silicon melt by directional solidification. Further the present invention comprises a method for preparing said silicon masteralloy.

Molded articles and methods for forming molded articles are provided. For example, a molded article comprises a first region formed by a first casting material and a second region formed by mixing a molten or liquid portion of the first casting material and a second casting material. The first casting material is a molten, liquid, or fluid metal alloy, and the second casting material is a molten or fluid metal alloy. The first casting material has a different chemical composition than the second casting material. The first region and the second region are cast as one integral casting using directional solidification, and the first region and the second region have different microstructure patterns. The molded article has a lower concentration of impurities than were present in the first and second casting materials, and an interface between the first region and the second region is devoid of an oxidation layer.

Molded articles and methods for forming molded articles are provided. For example, a molded article comprises a first region formed by a first casting material and a second region formed by mixing a molten or liquid portion of the first casting material and a second casting material. The first casting material is a molten, liquid, or fluid metal alloy, and the second casting material is a molten or fluid metal alloy. The first casting material has a different chemical composition than the second casting material. The first region and the second region are cast as one integral casting using directional solidification, and the first region and the second region have different microstructure patterns. The molded article has a lower concentration of impurities than were present in the first and second casting materials, and an interface between the first region and the second region is devoid of an oxidation layer.

The present invention comprises directionally solidified multicrystalline silicon ingots, a silicon masteralloy for increasing the efficiency of solar cells made from wafers cut from the silicon ingots, method for increasing the yield when producing multicrystalline silicon ingots from a silicon melt by directional solidification. Further the present invention comprises a method for preparing said silicon masteralloy.

Provided is a scintillator having a crystal containing CsI (cesium iodide) as a host material thereof and thallium (Tl) and bismuth (Bi), and a novel scintillator which maintains a high output and simultaneously can further enhance the afterglow characteristics. There is proposed a scintillator having a crystal containing CsI (cesium iodide) as a host material thereof and Tl, Bi and O, wherein the concentration a of Bi with respect to Cs in the crystal is 0.001 atomic ppma5 atomic ppm; and the ratio (a/b) of the concentration a of Bi with respect to Cs in the crystal to the concentration b of O with respect to I in the crystal is 0.00510.sup.4 to 20010.sup.4.

A stirring apparatus of an ingot casting furnace includes a rotating shaft and at least one fin. The fin is provided onto the rotating shaft, and has a first edge, a second edge of unequal length provided correspondingly, and a third edge connecting the first and the second edges. The rotating shaft can be driven to rotate, which consequently drives the at least one fin to stir materials in a crucible. The length of the first edge is different from that of the second edge in order for the materials in the crucible can be mixed with dopants more uniformly during the stirring process to produce ingots of stable quality.

Provided is a scintillator having a crystal containing CsI (cesium iodide) as a host material thereof and thallium (Tl) and bismuth (Bi), and a novel scintillator which maintains a high output and simultaneously can further enhance the afterglow characteristics. There is proposed a scintillator having a crystal containing CsI (cesium iodide) as a host material thereof and Tl, Bi and O, wherein the concentration a of Bi with respect to Cs in the crystal is 0.001 atomic ppma5 atomic ppm; and the ratio (a/b) of the concentration a of Bi with respect to Cs in the crystal to the concentration b of O with respect to I in the crystal is 0.00510.sup.4 to 20010.sup.4.

A combined thermal neutron detector and gamma-ray spectrometer system, including: a detection medium including a lithium chalcopyrite crystal operable for detecting thermal neutrons in a semiconductor mode and gamma-rays in a scintillator mode; and a photodetector coupled to the detection medium also operable for detecting the gamma rays. Optionally, the detection medium includes a .sup.6LiInSe.sub.2 crystal. Optionally, the detection medium comprises a compound formed by the process of: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound and heating; wherein the Group I element includes lithium.

A combined thermal neutron detector and gamma-ray spectrometer system, including: a detection medium including a lithium chalcopyrite crystal operable for detecting thermal neutrons in a semiconductor mode and gamma-rays in a scintillator mode; and a photodetector coupled to the detection medium also operable for detecting the gamma rays. Optionally, the detection medium includes a .sup.6LiInSe.sub.2 crystal. Optionally, the detection medium comprises a compound formed by the process of: melting a Group III element; adding a Group I element to the melted Group III element at a rate that allows the Group I and Group III elements to react thereby providing a single phase I-III compound; and adding a Group VI element to the single phase I-III compound and heating; wherein the Group I element includes lithium.