Grant: Discovery Grants Program - Individual

Despite the availability of solar energy to fulfill the worldwide energy demand, there is an urgent need for the development of efficient, reliable and cheap technologies for harvesting solar light and converting it into a useful energy. Our research concerns photovoltaic electricity for we propose the development of a new concept. The target is to bring the cost down to parity with electricity from fossil sources. Almost exclusively all current solar cells are based of the photoelectric effect where light of sufficient energy ionizes a material that transfers its charges to opposite electrodes. The principle generates its own limit where one single heterojunction has a maximum solar conversion efficiency of about 32%. Breaking that limit currently requires the use of several junctions mounted optically in series and known as tandem or stacked cells. We hereby propose the development of an alternative that does not rely on the photoelectric effect. That is the concept of light rectification that we borough from microwave antennas that are designed to convert microwave radiation into a direct current and photovoltage. It is well known that reception and conversion of microwave radiation currently reaches about 90% efficiency with optimized antennas. The objective of the present research is to extend the concept of rectification to optical frequencies where the antennas will scale with optical wavelengths and where rectification will take place at optical frequencies. We will develop arrays of antennas that pave the surface of solar devices and propose solutions to match impedances as well as to couple light successfully into the arrays. Those issues will be addressed by implementing a mix of chemistry, nanotechnologies, photonics and device development at Queen's University. Benefits of the research are expected on three scales: fundamental with the implementation of new nanophotonic structures for direct light conversion; technology with a new ultrahigh conversion efficiency paradigm that is amenable to self-assembling and large scale production; training of highly qualified personnel into a multidisciplinary research that opens new jobs related to clean and renewable energies.