Harvesting multiple optical energies using ZnPc/CdS-QDs hybrid organic/inorganic semiconductors

Abstract

The substitution of inorganic-based electronics by organic semiconducting materials is a current trend in science and technology for its economic and environmental benefits, but it is hardly progressing. The reason thereof is the lack of improved efficiency, which affects the organic semiconductors performance in many devices when compared with their inorganic-based counterparts. A recent peculiar idea of using heterostructures consisting of both organic and inorganic materials has become an auspicious solution. To this end, the ability to synthesize hybrid organic/inorganic semiconductors targeting different applications is of utmost importance. We hereby present a successful simple route to synthesize a stable homogenous hybrid organic/inorganic system consisting of zinc phthalocyanine (ZnPc) oligomers as the organic base, and Cadmium sulfide quantum dots (CdS QDs) as the inorganic part. The structural and optical characterizations of the prepared samples demonstrate new optical absorption transitions for the hybrids in the red region belonging to the ZnPc molecules, besides the original blue band absorption of the CdS QDs. This is combined with a reduced radiative emission of the whole system. Thus, the hybrid materials are capable of harvesting multiple frequencies within the visible spectra more efficiently than pure QDs, while relaxing non-radiatively rather than by emitting electrons or heat. These qualities favor the use of these hybrids as solar cell or thermal-power active materials.