Development and characterization of novel optoelectronic devices based on composite nanomaterials

Abstract

As for the SPR effects, three different material systems were investigated for potential LED and solar cell applications: PVA-ZnO/MWCNTs/PVA-ZnO, SiO2-Au core-shell/PVA-ZnO, and pure Au nanoparticles embedded organic polymer solar cells. The PVA-ZnO/MWCNTs/PVA-ZnO composite structures showed greatly enhanced band edge emission (>300%) that originates from SPR between ZnO and MWCNTs. As for the SiO2-Au core-shell structures, the SPR peaks can be tuned in a wide range (554 nm - 631 nm) by adjusting the size and the shape of Au nanoparticles attached to the SiO2 surface. The core-shell structures provide an effective approach for simultaneously suppressing defect level emission and enhancing near band edge emissions of the ZnO nanoparticles by defect-induced surface plasmon resonance. The superior SPR tunability of the core-shell structure, together with the low cost and flexibility of the approach, makes it a nanomaterial of high potential for future optoelectronics. Finally, SPR effect of pure Au NPs for inverted solar cell application was demonstrated. After embedded with a thin layer of Au NPs, a maximum efficiency improvement of 14.29% was achieved.