Plasmon multiwavelength-sensitized luminescence enhancement of highly transparent Ag/YVO4:Eu3+/PMMA film

The ultraviolet (UV)-blue radiation of sunlights usually induce the photodegradation of organic photovoltaic materials, leading to the lifetime degeneration of solar cells. A luminescent converter layer for UV-blue to visible photoconversion is a promising way to harvest UV-blue sunlights and transforms them into visible lights that can be directly absorbed by active materials of solar cells. In this work, highly transparent Ag/YVO4:Eu3+/PMMA film were fabricated, which could not only filter out the harmful UV light as well as absorb multiband wavelengths ranging of 400-540 nm, but also could convert them into red lights which match well with band gap of photovoltaic materials. Then, we experimentally and theoretically investigated the luminescence enhancements with various Ag nanoparticles (NPs) size, concentration and excitation wavelengths. The luminescent enhancements were realized under the multiband wavelength excitation ranging of 280-538 nm. The maximum luminescence enhancement is 23-fold for Ag/YVO4:Eu3+/PMMA film under the excitation wavelength of 468 nm matching well with the localized surface plasmonic resonance (LSPR) of Ag NPs. Furthermore, we provide evidence that such enhancement is resulted from excitation field enhancement instead of Purcell effect. Our findings provide us a thinking on designing highly effective and transparent plasmon/luminescent converter, which may be utilized to improve the photostability and efficiency of solar cells.