| Abstract
| - A novel and facile preparation method for layer-by-layer (LbL) self-assembled films incorporating quantumdots (QDs) and having intense photoluminescence (PL) from blue to red is presented. Functional sol−gel-derived glass layers prepared by the hydrolysis of 3-aminopropyltrimethoxysilane (APS) or3-mercaptopropyltrimethoxysilane (MPS) have been used as a linkage between QD layers. Absorption, PLspectroscopy, transmission electron microscopy, and atomic force microscopy were employed forcharacterization, which revealed that the QDs in the prepared films had a nearly close-packed coverageand were not aggregated. The PL efficiencies of the QDs (CdTe or ZnSe, both are thioglycolic acid-stabilized)dispersed in the films were roughly half that of the initial colloidal solutions but reached 24% before arefractive index correction. The thickness of the red-emitting film with 10 CdTe QD layers was ∼50 nm.The concentration of QDs in the film derived from the first absorption peak was ∼0.01 M. Because thePL starts to show a red shift, the obtained concentration is practically the ultimate one in the glass matrix.The mercapto, amino, and carboxyl groups play important roles in LbL self-assembling processes.
|
