A Novel Thermochemical Method for Fabrication and Theoretical Explanation of High Luminescent Mn-Doped CdS Nanoparticles

摘要

In this paper, fabrication and characterization of bare and doped CdS nanoparticles as well as investigating the luminescence properties of these particles as an important II-VI semiconductor are presented. A novel Thermochemical method was used for synthesis of these quantum dots. Thiols were used as the capping agent to prevent further growth during fabrication process. The application of TGA as a capping agent instead of TG was studied as a novel idea in this paper and was used practically in the synthesis of semiconductor nanoparticles. Using this process resulted in particles with sizes between 3 - 7 nm. Several samples were synthesized and characterized under various Mn ions doping ratio from 1:10 to 1:180, different temperatures from 40℃ to 96℃ and different pH values from 6 to 10. Synthesis of CdS nanoparticles with high Mn ions concentration resulted in luminescence decrement, while luminescence of nanoparticles was increased by decreasing Mn/Cd doping ratio until Mn:Cd = 1:180. The best fabrication temperature was obtained at 96℃ and the highest luminescence was observed at the pH value of 9. A theoretical explanation for the behavior of fabricated high luminescent quantum dots is presented based on the principles of quantum mechanics.