The Effect of Fatty Amine Chain Length on Synthesis Process of InP/ZnS Quantum Dots

Abstract

Obtaining narrow size distribution through conventional methods used for quantum dots of group II-VI semiconductors is impractical in the case of III-V semiconductors specially InP/ZnS quantum dots because of molecular precursors depletion and growth stage continuation through Ostwald ripening process. Using fatty amines as activator along with precursors can lead to more monodispersed quantum dots. In this work, the effect of fatty amine chain length on InP/ZnS quantum dots synthesis was investigated. Octylamine, dodecylamine and oleylamine were used as the activator of InP/ZnS quantum dots synthesis. Synthesis progress and color changes in reaction mixture with time lapse, indicative of formed quantum dots concentration, was intensified in presence of fatty amines with shorter chain length. Quantum dots with smaller mean size and broader size distribution were synthesized in presence of longer fatty amines as a result of higher capping capacity of them. Thereupon the optical properties of quantum dots were affected by chain length of fatty amine. Longer wavelength of photoluminescence emission was achieved by using octylamine with the shortest chain length among selected fatty amines.