Solar Cell Efficiency Enhancement Through Down-Shifting and Up-Converting Layers: the Ephocell Project: Luminescent Downshifting Quantum Yield Measurements

Organic cells and dye-sensitized cells developed to-date have a narrow active absorption range, relative to the spectral range of the available solar resource. Their efficiency could be significantly enhanced through a process of down-shifting (DS) and up-conversion of non-absorbable photons converting them to photons better matching the spectral response of the particular solar cell. The DS molecules must exhibit a large Stokes shift and high luminescent quantum yield when incorporated in the downshifting polymer layer. In this paper, the QY of a downshifting Europium (III) complex in solution is determined using two distinct experimental techniques. The QY is measured for varying concentration and at varying excitation wavelength