AnnuaireIMN Contacts

Ceses groupe

Nanomaterials for Solar Energy Conversion and Storage : photovoltaics, photobattery

In this field, our activity aims at making a technological breakthrough, by developing a device allowing conversion and storage of solar energy. This device should be efficient, low-cost and environmentally friendly: IIIrd generation photovoltaic cells with intermediate band (IB) and rechargeable photobattery.

Our strategy consists in analysing, modelling, understanding and exploiting the original properties of nanomaterials synthesised at IMN. The latter are precursors and photosensitive sols-gels based on Titanium oxide, in order to set up new photo-devices and optimize their performance. In parallel, we focus our effort on syntheses at low temperature to produce titanium oxides as harvesting materials for photogenerated charge carriers, in innovative devices and in hybrid organic solar cells (Bulk HeteroJunction, BHJ, in collaboration with CEA-INES). Chimie douce (Soft chemistry) processes were proved to be suitable for selectively isolate different allotropic TiO2 varieties, at temperature lower than 200°C while controlling the size, the shape of particle together with the nature of the crystalline facets. The nature of alkaline species (NaOH, TMAOH), the molar ratio, R=Ti/OH, and the ionic force of the reaction solution directly impact the morphology of titanium oxides. Choosing the suitable organic solvent allows us to optimize colloidal solutions of transition metal oxides whose physico-chemical characteristics render them compatible with wet printing processes: spin coating, ink jet.

Hydrolysis of [Ti8O12(H2O)24]Cl8.HCl.7H2O in organic solvents: colloidal solutions of anatase



The low temperature syntheses are greatly versatile. Optimising colloidal solutions of Titanium oxide allow us to produce thin films by chemical solution deposition: dip-coating, spin-coating, or ink-jet printing.

Hydrolysis of TiOCl2 in organic solvent: sols and gels of Titanium oxide


Controlling the condensation of commercial «TiOCl2» reactant in N,N dimethylformamide allows to synthesise sols and gels presenting original photo-electrochemical properties.12

Interactions between TiO2 nanoparticles and biomolecules

tio2On the basis of CESES team's knowledge on TiO2, a new research axis was born in 2011, in collaboration with PMN team of IMN and ISD team of INRA. We aim at characterizing the surface of titanium oxide nanoparticles in the presence of biomolecules, on one hand to understand the interactions between the inorganic semiconductor compound and the bio-organic molecules which can be in contact, and on the other hand to identify the photo-induced mechanisms at the oxide-solution interface under UV illumination.

Nanotubes or nanoribbons of Na titanates, precursors for anatase or TiO2(B)



Reaction of a gel of Titanium oxide hydrate (TiOCl2 + NH3 aq) with concentrated sodium hydroxide leads to alkali titanates. Their morphology affects the one of titanic acids, obtained after ionic exchange in acidic medium, and then also the morphology of titanium dioxide after thermal treatment. Optimising the experimental conditions allows us to quantitatively obtain various shapes: nanotubes or nanoribbons.