Energy Conversion
Solar energy materials and solar cells (photovoltaics)
Catalysis for Renewable Energy and Chemicals
Catalysis for Fuels and Chemicals (Hydrocarbon Conversion)
Solar Energy Materials and Solar Cells (Photovoltaics)
We are focusing on enhancing the efficiency of photovoltaic (PV) solar cells while making them cheaper, with the aim of making photovoltaics viable or large-scale energy conversion. Our research specialises in the fabrication of thin film solar cells and materials, and their advanced characterisation.
In particular, we work on cadium telluride (CdTe), novel sulphide materials and transparent conductors. We have demonstrated device structures having ‘superstrate’, ‘substrate’ and nanowire architectures and on flexible foil substrates. Typically, our research work focuses on a basic materials problem and then uses the understanding in the fabrication of an improved PV device.
Examples have included the control of grain size and doping in absorbers, the design of optical structures and the use of new doping routes in transparent conductors. Our best, one of a kind CdTe device had an in-house efficiency of 16.5% under Air Mass 1.5 illumination. We have facilities for sublimation growth, sputtering, metallisation, and measurements of efficiency, current transport, quantum efficiency and spectrophotometry.
Waste heat
The recovery of waste heat offers enormous potential for improved energy efficiency and reduced production of greenhouse gases. Our research focuses on two different approaches: thermoelectric and thermophotovoltaic devices.
Thermoelectric materials generate electricity from a temperature difference and are of particular interest for the automotive industry. Thermophotovoltaic devices operate on the same principle as solar photovoltaics, but with infrared light from heat sources. They have potential for heat recovery from sources as diverse as furnaces used in the glass and cement industries and domestic central heating boilers.
We are working on novel thermoelectric materials based on strongly correlated oxides, and on novel thermophotovoltaic materials based on so-called highly mismatched semiconductor alloys containing nitrogen and bismuth. Our expertise includes bulk and epitaxial crystal growth and a range of advanced characterisation techniques.
Catalysis for Renewable Energy and Chemicals
We utilise our expertise in catalysis to address green chemistry and energy reactions, with a particular interest in developing new catalysts and efficient routes to renewable chemicals from biomass and carbon dioxide (CO2). As some of these targets will require the development of new and advanced materials, we are developing these materials in partnership with colleagues from the Department of Chemistry and the Materials Innovation Factory.
In particular, we are studying novel nanostructured oxides, semiconductors, metal nanoparticles and porous polymers, using high-throughput automated instruments for synthesis, characterisation and testing. We are also exploring the application of non-conventional technologies, such as photocatalysis and microwaves.
In addition to rapid discovery, high-throughput methods, if coupled with spectroscopy and characterisation, can aid in generating more fundamental advances, such as generating structure-activity relationships in catalysis.
Find out more about the Microbiorefinery here
Catalysis for Fuels and Chemicals (Hydrocarbon Conversion)
Clean and energy-efficient production of fules and chemicals relies on the development of mild transformations of hydrocarbon resources. To realise these transformations, more active and selective catalysts for activation of inert C-H and C-C bonds in hydrocarbons must be developed.
Our research focuses on teh rational design of highly active, soluble catalysts for selective functionalisation of C-H and C-C bonds and activation of small molecules to enable shorter, safer and cleaner routes to fuels and value-added chemicals.
Photocatalysis
Many chemical reactions, including natural photosynthesis, are powered by absorbing light. These reactions can be made faster using photocatalysts. Our research focuses on photocatalytic energy conversion reactions, including water splitting and CO2 reduction, to produce solar fuels such as hydrogen, methane and methanol.
We specialise in the synthesis, characterisation and testing of new photocatalysts, especially metal organic complexes and nanocrystals both in solution and on surfaces. Using advanced optical spectroscopy, we have obtained fundamental insight into the functioning of photocatalytic nanomaterials. Our experimental work is complemented by theory and modelling of photocatalysis as well as simulation-assisted exploration of innovative photocatalytic strategies.
We are also interested in more complex hybrid materials that improve the performance of photocatalysts, and the development of so-called ‘Z scheme’ multicatalyst systems, which mimic the transport of electrons during photosynthesis.
Additionally, we are exploring some selective organic reactions in order to elucidate whether a photocatalytic route can compete with conventional thermal catalysis.
Find out more about the photocatalysis research group here
Solid Oxide Fuel Cells
The Stephenson Institute’s scientists and engineers are working together to identify new candidate materials for fuel cell systems and understand the chemical and structural factors that contribute to their performance.
As solid oxide fuel cells (SOFC) technology matures and new applications are identified, we are looking to develop the next generation of SOFC materials that will deliver improved performance, have increased durability and lifetime, and reduce the cost of commercialisation.
We deliver high-throughput materials discovery, development and characterisation, specifically in mixed-ionic conductors for cathodes and pure ionic conductors for electrolytes.