Organic Molecule Assisted Synthesis And Properties Of Semiconductor Nanostructures

The goal of this dissertation is to enrich and develop hydro-/solvothermal route. Several representative semiconductor functional materials were successfully controllable synthesized by organic molecule assistance. The morphologies of the products were realized by adjusting the reaction conditions. And the formation mechanism and optical properties of products are also discussed. It is expected that the as-obtained products possess some novel physical and chemical properties. The details are summarized as follows:1. Alveolate amorphous Sb2S3 microspheres about 3μm in diameter were hydrothermally synthesized in aqueous solution without surfactant at 180℃using SbCl3, L-cysteine and tartaric acid as starting materials. After annealed at 250℃for 3 h in nitrogen atmosphere, polycrystalline Sb2S3 hollow spheres were obtained. Results show that tartaric acid and L-cysteine play a key role in the formation of such hierarchical structures. In addition, the possible aggregation mechanism was proposed to illustrate the formation of Sb2S3 microspheres based on the experimental results and analyses. The above results of research have been published in European Journal of Inorganic Chemistry.2. Hollow octahedral Zn2SnO4 (ZTO) hierarchical structures were hydrothermally synthesized starting from Zn(Ac)2, SnCl4 and L-lysine in NaOH solution at 200℃. The XRD result indicates a face-centered cubic phase for the as-prepared octahedral ZTO product with lattice constant a of 0.8650 nm. Results also demonstrate that the adding amount of NaOH and L-lysine has an immense function in the morphology control of octahedral ZTO hierarchical structures. The photoluminescences of the as-fabricated ZTO products with different shapes all display a broad strong green emission band at 500～600 nm but different in intensity at room temperature. The above results of research have been published in Chinese Journal of Inorganic Chemistry. 3. Cadmium sulfide rod-bundle structures decorated with nanoparticles have been synthesized via calcinations of inorganic/ organic composite precursor. The precursor was hydrothermally synthesized at 180℃using thioglycolic acid (TGA) and cadmium acetate as starting materials. The composition and phase structure of the precursor were investigated in detail. After detailed analyses, the precursor could be defined as CdS0.65/Cd-TGAo.35 and further completely transformed to wurtzite CdS through a thermal decomposition process at 400℃in air. The photoluminescence (PL) intensity of precursor is about hundred times than that of wurtzite CdS while with the same PL position. And when using ethanolamine and water as mixed solvent, wurtzite CdS nanocrystals with bullet-like morphology were synthesized by oleic acid assisted. Finally, cadmium chalcogenide (CdE, E= Se, Te) polycrystalline nanotubes were realized from the precursor at room temperature. The transformation from the precusor to CdSe and CdTe nanotubes were performed under constant stirring at room temperature in aqueous solution containing S2-, Se2- and Te2-, respectively. The nanotube diameter can be controlled from 150 to 400 nm related to the dimension of precursor.