Glasgow Caledonian University has developed a novel optical concentrator capable of providing gain on two planes. Such a concentrator can be used in a non-tracking wall mounted BIPV system.
The concentrator provides higher optical gains than alternative optical elements, thereby reducing the amount of PV cell (and silicon) required. Additionally, carefully selected FOVs (Field-of-Views) contribute to capture solar radiation throughout the day and all year round, removing the requirement for electromechanical tracking.
Further, the optical structure has been designed to take into account the fact that the sun’s path deviation from summer to winter is far less than the deviation from sunrise to sunset and the entrance aperture and concentrator profile have been optimsed to redirect sunlight to the exit aperture and to the PV material.
A concentrator PV-array based on this structure is also capable of providing ambient light to building interiors.
The reduction of PV material can be particularly important in applications using Gallium Arsenide PV cells.
The optical element can be used not only for solar energy systems (solar PV and solar thermal), it also could be used to collect visible and infrared radiation in applications such as sensing and optical wireless communications.
- Reduction in cost of BIPV systems
- High optical gain
- High electrical power output
- Optimum collection of light at a variety of angles of incidence
- No electrical tracking required
- Provides illumination as well as energy generation
- Reduction in CO2 emissions
- BIPV Systems
- Optical sensing
- Optical wireless communications
The technology is protected by a granted GB patent and international patent application (Priority date December 2011), now in Regional/National phase.
Small prototypes have been built and tested with extremely positive results. Larger prototype array units have now been completed and initial results have confirmed these impressive results with high levels of optical gain generated.
The state of the art anode material used in Solid Oxide Fuel Cells is the Ni/YSZ ceramic-metal (cermet) composite (where YSZ = Y2O3/ZrO2) which has several difficulties in use. The anode is prepared as NiO/YSZ, and must be reduced to Ni/YSZ to work: this entails a large volumetric shrinkage, which can cause the cells to crack. Ni is a good catalyst for cracking hydrocarbon fuels, but tends to produce solid carbon, which then blocks the electrode, lowering performance and effective working life. The metallic Ni phase is also mobile and tends to sinter over time, again lowering performance.
Our technology overcomes these problems while achieving a comparable electrochemical performance, electrical and catalytic properties (significantly better when used with methane fuel). The new perovskite anode shows better tolerance to hydrocarbon fuels, without depositing carbon on the electrode. The perovskite anode can withstand more repeated cycling than a Ni/YSZ anode.
- As effective as existing materials but without the problems such as cell cracking and reduced effective working life.
- Redox stable – no cracking on cycling.Highly tolerant of hydrocarbon fuels.
- Resistant to carbon deposition.No need for initial cell reduction.
- The perovskite anode can be used in any Solid Oxide Fuel Cell (SOFC) instead of Ni/YSZ, where redox stability or hydrocarbon use is needed. This covers most applications of SOFCs.
- The University would welcome enquiries from commercial parties interested in developing commercial applications of fuel cells and fuel cell materials.
The University of St Andrews has granted patents in Japan, USA, Canada, China, Australia and Europe (GB, France, Denmark, Switzerland, Italy, Spain, Austria and Germany) and continues to perform R&D in advanced materials for fuel cells. The University is looking for a licensee to the patents and knowhow or a commercial collaborator to take it to market. Patent Numbers: PCT/GB2003/003344, Granted patents: US 7,504,172 , Europe 1532710. Additional information can be made available under a confidentiality agreement.
The use of TADF emitters represents a paradigm shift in emitter development wherein inexpensive small molecule organic compounds can now be used to harvest 100% of the excitons in an electroluminescent device and so obtain excellent power efficiencies. We have developed a series of deep blue TADF emitters for Organic Light-Emitting Diodes (OLED).
TADF allows purely organic emitters to harvest the triplet states as an alternative to the existing heavy-metal based phosphorescent OLEDs, which are known to be expensive and environmentally hostile. The emitters contain both carbazole donors and oxadiazole acceptors to effectively form excitons by a charge trapping mechanism. The blue colour emission wavelength of these emitters can be a valuable asset as there is currently a dearth of bright blue-emitting phosphorescent emitters for OLEDs.
The invention is primarily used for blue-emitting OLEDs or, when operating in parallel with green and red emitters, for energy-efficient white lighting devices. Due to the nature of TADF, potential applications also include temperature or oxygen sensors.
- Harvesting 100% of excitons via TDF for OLED devices
- Inexpensive organic emitters
- Environmentally more benign
- Deep blue emission colour
- Ambipolar characteristic
- Blue-emitting OLEDs
- To operate in parallel with red and green emitters for energy efficient white light devices
- Due to the nature of TADF, potential applications also include temperature or oxygen sensors
Subject to UK patent application number 1507340.6 filed 29 April 2015.
Roll-to-roll printing of plastic electronics from solution promises to revolutionise the manufacturing of luminaires, offering a cheap and scalable method of fabricating high-efficiency light sources. White light displays are the holy grail of this endeavour and require efficient red, green and blue emitters. So far, red and green emitters using iridium-based complexes have been synthesised, but efficient and stable blue light emitter design is still a challenge in the industry. To tackle this, we have designed deep-blue emitting cationic iridium complexes that are unprecedentedly bright. A tethering strategy, where the distal components of the ligand scaffold are rigidly linked together, drastically enhances the brightness of these emitters while simultaneously invoking a deep blue colour due to the ligand’s strong electron donating capabilities.
Our rigidifying strategy differs from typical strategies that use multi-dentate ligands, which are synthetically challenging to access; our strategy uses established straightforward protocols to access these complexes.
The invention is primarily suited for OLED or LEEC application for visual display and lighting applications. Due to the charged phosphorescent nature of the emitter, applications relating to bio-imaging, analyte detection and oxygen sensing are also feasible.
- Deep blue emission
- Enhanced brightness from steric bulk and rigidified ligand scaffolds
- Straightforward synthesis through established protocols
- Highly soluble in organic solvents makes solution processing and roll-to-roll printing of optoelectronics possible
- OLEDs for visual displays & lighting applications
- LEECs for visual displays and lighting
- Due to the charged phosphorescent nature of the emitter applications relating to bio-imaging, analyte detection and oxygen sensing are also feasible
Patent granted – US10236454B2