High-quality chalcogenide/oxide and manganese-doped semi- conductor nanocrystals (NCs) are inspired by thermoelectric and spintronic applications. Recently, we successfully synthesized mono- disperse NCs of PbSe, PbTe, Bi 2 Te 3 and In 2 O 3 with shape- and size- control by employing a high-temperature organic solution approach, demonstrating the feasibility of this synthetic strategy. (1) Investi- gations of In 2 O 3 NCs ( JACS JACS, 127 , 5276, 2005, top-left) imply that each NC is a single crystal with high-crystallinity, and the size of NCs is tunable. (2) A mechanism study of PbTe nanocrystalline evolution ( JACS JACS, 126 , 11798, 2004, top-right) indicates that the shape of PbTe NCs can be developed from spherical to cubic structure when certain experimental parameters are well controlled. (3) A novel method for the large-scale, shape-controlled synthesis of 1D corrugated Mn- doped PbSe nanoarrays without using any capping polymer or ionic surfactant was developed ( JACS JACS, 126 , 14816, 2004, bottom-left). (4) A unique synthesis of discrete, single-crystal, defect-free and hexa- gonal Bi 2 Te 3 nanoplatelets was achieved, and a two-step epitaxial growth of the cylindrical strings of Bi 2 Te 3 nanoplatelets on the Te rod surface by packing them along c-axis in a top-bottom-top- bottom sequence was proposed as well ( JACS JACS, 127 , 10112, 2005, bottom-right). (5) To extend this synthesis approach to III-V semiconductor system, we are progressively synthesizing Mn- hesis, Characterization and Evolution Mechanism Stu hesis, Characterization and Evolution Mechanism Stu of Semiconductor Nanocrystals of Semiconductor Nanocrystals Jiye Fang, University of New Orleans, DMR-0449580 IMAGES: self-assembled In 2 O 3 mono- layer pattern (TEM, top-left), self- assembled cubic PbTe monolayer pattern (TEM, top-right), in-situ self-assembled Mn-PbSe nanoarrays (SEM, bottom-left) and single-crystal, defect-free and perfect hexa-gonal Bi 2 Te 3 nanoplatelets (TEM, bottom-right).