Research Area

LPI pioneered research on semiconductor nanocrystallites and mesoscopic oxide films. These new materials have found important applications in a variety of fields, particularly in dye sensitized solar cells (DSC) lithium insertion batteries and electrochromic displays. By covering the surface of the mesoscopic oxide films with a suitable molecular chromophore efficient harvesting and conversion of sunlight into electricity can be achieved. The overall power conversion in full sunlight reaches presently over 11 %. Current research focuses on optimization of key parameters such as spectral response, photocurrent, photo-potentials and long-term stability. Fundamental studies concern electron and energy transfer reactions in these mesoscopic systems. Ultrafast interfacial electron transfer down to the femtosecond time domain and lateral charge percolation processes on the surface of insulating oxide nanoparticles are being investigated. Electrochemical studies currently underway include those on oxygen reduction in solid oxide fuel cells and the use of mesoscopic oxide films in lithium insertion batteries as well as in electroluminescent and bioelectronic devices. Photo-electrochemical studies concern visible light induced water oxidation on semiconductor oxides and the combination of the latter with a dye-sensitized solar cell in a tandem device to split water into hydrogen and oxygen by sunlight. The photo-degradation of toxic industrial wastes and pollutants is also being investigated. Finally LPI pioneered the development of new ionic liquids, which are used as "green" electrolytes in solar cells and other electrochemical devices