Optical, thermophysical and electrical characterization of PMMA (CdSe QDs) composite films

The concentration dependence of optical, thermophysical and electrical behavior, based on poly-methyl methacrylate filled with CdSe quantum dots (PMMA(CdSe)) have been investigated. The PMMA(CdSe) concentration was 0.001, 0.005, 0.01 and 0.05 wt.%. The composites were prepared in the form of films by the solution casting technique. The optical properties of PMMA(CdSe) films have showed that, there is a red shift of the absorption and photoluminescence (PL) after the QDs were added into PMMA. The PL peak intensity of the composite was enhanced by ≈ 2.5 times compared to the CdSe QDs. The thermal conductivity (k) was obtained by measuring the thermal diffusivity (α) and thermal effusivity (e) using the photoacoustic (PA) technique. The composites exhibit ≈ 120 % improvement in k at 0.05 wt.% . Furthermore, the dc electrical conductivity measurements of pure and doped PMMA, showed that the obtained values were enhanced about four orders of magnitude for the highest concentration compared with pure PMMA at 500 0C.