by Professor Michael Grätzel
Jun 25, 2014
Professor Michael Grätzel, gave a lecture on June 25, 2014 titled "Light energy harvesting and charge carrier collection in mesoscopic solar energy conversion systems".
Solar cells using dyes or semiconducting pigment particles as light harvesters supported by mesoscopic oxide films have emerged as credible contenders to conventional p-n junction photovoltaics. Separating light absorption from charge carrier transport, dye sensitized mesoscopic solar cells (DSSCs) were the first to use a three-dimensional nanocrystalline junction for solar electricity production. molecularly engineered donor-acceptor porphyrine dyes reach currently a power conversion efficiency (PCE) of up to 13% under standard air mass 1.5 (AM1.5) reporting conditions (25°C, 1000 Watt/m2 solar intensity).
Recently an amazing breakthrough was witnesses with the advent of metal halide perovskites as powerful light harvesters for thin film photovoltaics. Solid state mesoscpic cells based on CH3NH3PbI3 pigments supported by a nancorystalline TiO2 scaffold and organic or inorganic hole conductors have now reached a certified power conversion efficiency of 17.9% and further rapid improvements in performance appear to be feasible.
