Materials for energy conversion
To create a energy system based on renewable energy, improved and new solutions for energy conversions are required. This also requires new materials, both those that are directly involved in the energy conversions, such as photocatalysts, or photon absorption materials for photo voltaics; but also other materials needed to create complete devices operating in real-life conditions. Within the research programme of inorganic chemistry, research is conducted into new semiconductor materials by solution chemistry, as well coating materials with tuneable optical properties with applicability fore renewable energy conversion.
Semiconductor materials for energy conversion
New solution based synthesis routes to nano-structured complex composition semiconductors are developed with a particular interest in controlling the atomic structure and exposed surfaces of the semi-conductor oxide, as well as the structure of dopants. The semi-conductor oxide structures may be doped for optical up-conversion, sensing, photon splitting, magnetic semiconductors, and photo-catalysis of fuel from water. Typical oxides studied are TiO2, ZnO, Fe2O3 and binary oxides. Low temperature, durable and highly active photo-catalyst coatings on aluminum and steel are also developed together with industry.
Contact person: Prof. Gunnar Westin
Optical coatings for energy applications
Coatings with tunable optical properteies are applicable in several ways in the contect of energy conversion. They can function as passive components in a device: providing mechanical protection (in combination with transparency at suitable wavelenghts), or giving wavelength-selective reflection or transmission to a surface. They can also function as optically active components for photo chemistry or photovoltaics. Within the inorganic research programme, we are currently running projects based on two classes of materials:
High-entropy or multi-component nitride coatings, based on early transition metals. Early transition metal nitrides are metallic conductors, and can exhibit plasmonic properties which e.g. gives TiN it's golden colour. High entropy solid solution phases provides an unpresidented possibility to mix different metals, and control the electronic structure of the nitrides, and thereby tune the optical properties of these nitrides.
AlN-based coatings. AlN is a large band gap semiconductor and insulator which is transparent un the infrared, visual, and near-UV range. Through the formation of solid solution, and the formation of nanocomposite structures, mechanical and optical properties can be tuned. These coating materials have demonstrated tuneable absorption edge and optical band gap (in the range 5.8-2.5 eV) in combination with high mechanical strength (up to 30 GPa).
Contact person: Ass. Prof. Erik Lewin
Oxide semiconductors for solar fuels and self-cleaning surfaces.
Contact person: Prof. Gunnar Westin