Investigation of CdSe quantum dots embedded in copper phthalocyanine thin films

Semiconductor quantum dots (QDs) are essential components in composites for tailoring optical and electrical properties. We have reported the synthesis of cadmium selenide (CdSe) QDs via a simple solvothermal route. The composite layers of copper phthalocyanine (CuPc) and CdSe QDs were prepared by spin coating. The synthesis of uniform, narrow-size-distributed CdSe QDs was confirmed using UV-Vis and TEM images. The XRD pattern of the CdSe composite showed a cubic crystal structure with diffraction planes of (111), (220), and (311). The peaks associated with CuPc were observed at lower angles. A clear systematic enhancement in the optical absorption of the visible region is directly proportional to the concentration of CdSe in the composite layer. The thermo-gravimetric analysis confirmed a noteworthy enhancement in the thermal stability of the composite layers in comparison with pristine CuPc. The concentration of the CdSe QDs in the composite also controlled the surface morphology. The efficient charge separation between QDs and polymers is due to the maximized interface between them, which enhances the charge transport for the development of high-efficiency hybrid solar-cell devices.