Papers by Author: De Ren Yang

Abstract: The behaviors of isovalent impurities doped in Czochralski (CZ) silicon crystal have attracted considerable attention in recent years. In this article, a review concerning recent processes in the study about germanium in CZ silicon is presented. The disturbance of silicon crystal lattice in and the influence on the mechanical strength due to germanium doping is described. Oxygen related donors, oxygen precipitation and voids defects in germanium doped Czochralski (GCZ) silicon has been demonstrated in detail. In addition, the denuded zone formation and the internal gettering technology of GCZ silicon is also discussed.

Abstract: A TGA assisted hydrothermal process was employed to prepare chalcogenide nanorods. The different morphology of CdS nanomaterials prepared with and without the TGA assisted hydrothermal process indicates that TGA plays a critical role in controlling the nucleation and growth of CdS nanomaterials. The paper makes a preliminary presentation of the mechanisms of preparation of chalcogenide nanostructures with and without the use of the TGA assisted hydrothermal synthesis. FeS nanorods and nanoparticles have been prepared by the TGA assisted and without the TGA assisted hydrothermal process, respectively, which confirmed the proposed mechanism. X-ray diffraction (XRD) shows that the nanorods are of orthorhombic structure, and selected area electron diffraction (SAED) pattern showed that the FeS nanorods were single crystalse. Further investigation for the synthesis of other chalcogenides will be undertaken in order to confirm the proposed mechanism.

Abstract: Star-shaped and rod-like PbS crystals have been successfully prepared by a novel thioglycolic acid (TGA) assisted hydrothermal method. X-ray diffraction (XRD) reveals that the PbS crystals are of the cubic rock-salt structure and well formed. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observations show that the morphology of PbS nanocrystals is easily controlled according to sulphur source, lead source, and pH value. Furthermore, the paper gives a preliminary presntation of the mechanism and the critical role of the TGA-assisted hydrothermal synthesis of PbS nanorods