Oskam´s Research Group
The Center for Research and Advanced Studies of the National Polytechnic Institute
We synthesize the nanomaterials with different morphology and from various methods such as hydrothermal, electrrochemical and microwave-assisted method. We use structural, optical and textural characterization including X-ray diffraction, SEM, Uv-Vis Raman spectroscopy and Rheology characterization to obtain information on crystallographic structure, morphology and texture of our materials.
We work on following research lines:
Synthesis, characterization and applications of nanomaterials
In photovoltaics, our efforts are mainly focused on the dye-sensitized solar cell (DSC). Recently we have developed our research lines to Perovskite solar cells. DSC is based on a mesoporous, nanostructured metal oxide substrate, sensitized to sunlight through the adsorption of a molecular dye. We have investigated the influence of the nanomaterials properties on the performance of the solar cells, using TiO2 in both the anatase and brookite form, and ZnO prepared by a variety of methods and with a range of morphologies.We characterize our cells by different electrochemical tecniques such as electrochemical impedance spectroscopy (EIS), intensity-modulated methods, including photovoltage (IMPV) and photocurrent spectroscopy (IMPS) to calculate the internal parameters like recombination resistance, electron diffusion coefficient and life time.We also are making progress in the scale-up of the technology fabricating mini-modules of 24 cm2, reaching an efficiency of 4.8% for the DSCs based on anatase (in active area).
Photoelectrochemical solar cells
Here, we focus on selective coatings that efficiently absorb sunlight but with a low thermal emittance, thus optimizing the conversion efficiency and minimizing loss processes. We use both electrodeposition and sputtering to prepare selective coatings, using cermet and multilayer stack approaches in order to tailor the optical properties of the thin films. Specific examples for Ni and Co black, and Al2O3-MoOx-Al2O3 systems will be presented.
For this research line, we use a combinatorial technique to find new metal oxide nanomaterials for solar water splitting. In addition, we use advanced (photo)electrochemical methods in order to study the fundamental processes taking place in promising nanomaterial, analyzing the hole transport and recombination properties using intensity-modulated methods, including photovoltage (IMPV) and photocurrent spectroscopy (IMPS). We have recently obtained interesting results for the p-type semiconductor CuBi2O4.