Insights into the formation of an emissive CdTe-quantum-dots/cellulose hybrid film

Optical and electrical modifications of a highly hydrophilic cellulose regenerated (RC) thin film as result of the inclusion in the film structure of cadmium-tellurium covered with mercaptosuccinic acid quantum dot nanoparticles (CdTe-MSA QDs) are analysed. CdTe-MSA QDs nanoparticles inclusion was performed by dip-coating of the RC film in an aqueous nano QDs solution, and two different immersion periods (2 h and 24 h) were considered. Impedance spectroscopy measurements, which can give information of changes in both film surface and bulk phase were performed for CdTe-MSA QDs inclusion confirmation as well as the estimation of electrical changes associated to QDs modification. Optical characterization of the original support and the CdTe-MSA(2 h) and CdTe-MSA(24 h) modified films was carried out by light transmittance and ellipsometry spectroscopy (at three different take-off angles). According to these results, the inclusion of CdTe-MSA QDs practically does not reduce the high transparency of the film support, but it increases the reflexion index and extinction coefficient of both modified films. Moreover, fluorescence and XPS measurements were also performed for more complete information on the effect caused by the presence of CdTe-MSA QDs in the cellulosic film. A comparison of changes in physicochemical properties of the cellulosic/CdTe-MSA QDs films and those modified with other nanoparticle quantum dots is also performed.