Colloidal Synthesis Of Copper-based Semiconductor Nanocrystals And The Study On TheirCharacterization And Growth Mechanism

Copper sulphide (Cu2-xS,0<x<1) semiconductor is a material developed after the â…¡-â…¥å'Œâ…£-â…¥ chalcogenide with low toxicity and non-heavy metal elements. It has broad application potential in many fields, ranging from photovoltaics to optoelectronic and bio-imaging. To date, different research on the copper sulphide nanomaterials has been widely invested in, from the colloidal synthesis of various components to the Localized Surface Plasmon Resonances (LSPRs), as well as the photoelectric and biological fields. Currently, worldwide groups are all considering the copper sulphide as a research hot spot, which this material can act as reaction source or catalysis in the synthesis of heterostructure or hybrid structure nanocrystals. All these researches are accelerating the copper sulphide to make a huge breakthrough in the industrialization.As a typical wet-chemistry method, dodecanethiol mixed with octadecene or oleylamine could act as sulfur source and capping agent. In this dissertation, different synthetic strategies (one-pot and the injection) have been used to obtain a series of copper sulphide-based products. Based on those products, a systematic study was carried out to characterize of the change of the components and morphology in Cu-Zn-S semiconductors nanocrystals. Besides, the controllable synthesis of the heterostructure and hybrid structure nanocrystals, which originated from the djurleite (CU1.94S) had been succeeded. Also, the growth procedure of these nanocrystals was analyzed.At first, in the one-pot reaction system, we succeeded in adjusting the moral ratio of the copper to the zinc source to convert the products, from the Cu(I):ZnS quantum dots to the Cu1.94S-ZnS heterostructure nanocrystals, and in the extremely high moral ratio of copper to the zinc source, we obtain the digenite nanocrystals, which had also been monitored by the variation with the LSPRs in the transformation procedure of phase and composition. Afterwards, four kinds of different compounds with the heterostructure, which were all based on the copper sulphide, had been synthesized through the injection method. Besides, a reasonable growth mechanism was suggested. At last, we further synthesized the copper sulphide based I-III-VI2hybrid structure nanocrystal in the one-pot system and proposed a similar growth mechanism.Our study on the copper sulphide-based nanocrystals proves the advantage of the high reaction activity of the copper sulphide. This research on the doping, heterostructure and hybrid structure system could be a great foundation to the further study on the copper sulphide nanocrystals.