Preparation and characterization of self-assembled thin film of MPS-capped ZnS quantum dots for optical applications

Abstract

For this study we prepared colloidal ZnS quantum dots using 3-mercaptopropyltrimethoxysilane (MPS) as the capping agent. Colloidal ZnS quantum dots were directly deposited on glass substrates by a spin coating process. Therefore self-assembled films made of ZnS quantum dots in a SiO2 network were obtained using only one production step. The films were heat-treated at 100 degrees 125 degrees 150 degrees 175 degrees and 200 degrees C in an N-2 atmosphere. The results showed that the dimension of quantum dots changed from 2.8 nm to 3.2 nm by heat treatment. The refractive index extinction coefficient thickness and dielectric coefficient values of the films were calculated. The present study showed that size and the refractive indices of films can be controlled by the heat treatment. Therefore such films can be a good candidate in optical filter applications.