A study of optical properties of PbS quantum dots prepared by thermal injection

• Main Authors: Guo-Shih Fan, 范國是
• Other Authors: Yu-Hsu Chang
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/ndn78r

碩士 === 國立臺北科技大學 === 資源工程研究所 === 106 === In this project, the lead sulfide quantum dot is synthesized by a hot injection method. Thioacetamide is used as the precursor of sulfur and lead chloride is used as the precursor of lead. Two reagents are dissolved in oleylamine solvent seperately and then thioacetamide-oleylamine is injected into a solution containing lead chloride-oleylamine under nitrogen atmosphere. The reaction temperature is controlled at 75°C and the reaction time is 15 minutes. At the end of the reaction, the oleic acid is replaced by oleylamine via ligand exchange process. After centrifugation, lead sulfide quantum dots with the particle size of about 5.1 nm are observed by TEM. The absorption wavelength of 1070 nm and the emission wavelength of 1150 nm are measured by NIR spectrometers and PL, respectively. The tantalum pentoxide substrate is immersed in a piranha acid forming hydrophilic surface and then modified with trimethoxy (7-octen-1-yl) silane or octadecyl trimethoxy silane. The silanes have been successfully attached to the surface of tantalum pentoxide film confirmed by AFM and FTIR. The lead sulfide quantum dot solution is then deposited on the surface of the tantalum pentoxide film by spin coating. Subsequently, the lead sulfide quantum dot solution is deposited by spin coating on the surface-modified tantalum pentoxide film. The roughness of 5.59 nm and 3.58 nm are observed by AFM. The surface morphology of the lead sulfide quantum dot film is observed by FE-SEM and the particle size is found to be non-uniform, with a size of about 6-13 nm.