Polymer nanocomposite luminescent films for solar energy harvesting made by concurrent multi-beam multi-target pulsed laser deposition

Abstract

We report on the polymer nanocomposite films doped with the nanoparticles of rare-earth (RE)-doped fluoride phosphor NaYF4:Yb3+,Er3+ (molar proportion: a = 3% of Er3+, b = 1 to 5% of Er3+, and [100% - (a + b)] of Y3+) for efficient luminescent solar concentrators (LSCs). The films are deposited using the concurrent multi-beam multi-target pulsed laser deposition of the inorganic target material and matrix assisted pulsed laser evaporation of the polymer (MBMTPLD/MAPLE). Polymer poly(methyl methacrylate) known as PMMA was evaporated and deposited on a glass plate from its solution in chlorobenzene frozen in liquid nitrogen with the fundamental harmonic (1064 nm) of a Q-switched Nd:YAG laser concurrently with the inorganic phosphor target ablated with the 2-nd harmonic (532 nm) of the same laser. The sun light is absorbed by the phosphor nanoparticles embedded in the 250-nm thick polymer film and converted in near-infrared (NIR) radiation via the mechanism of downconversion (quantum cutting). The NIR radiation propagates via the glass plate as a light guide and is converted in electric power with photovoltaic cells attached to the edges of the plate. The advantage of the proposed polymer nanocomposite LSCs is a broad absorption spectrum covering a significant portion of the solar radiation spectrum, high spectral conversion efficiency, and low reabsorption due to minimal overlap between the absorption and emission spectra (large Stokes shift). The power concentration factor of the polymer nanocomposite LSC is expected to be of the order of 10.