“Because sunlight is made up of many colours of different energy, ranging from the high energy ultraviolet to the low energy infrared, a combination of solar cells of different materials can convert sunlight more efficiently than any single cell,” Professor Green said.
Professor Green, with colleague Dr Anita Ho-Baillie, led the team that developed a silicon cell optimised to capture light at the red and near-infrared end of the spectrum. That cell was able to convert up to 46 per cent of light into electricity. When combined with four other cells, each optimised for different parts of the solar spectrum, the five-cell combination converted 43 per cent of the sunlight into electricity, bettering the previous world record by 0.3 per cent.
“Our group’s silicon cell was the key contributor to the new result,” Professor Green said.
Professor Stuart Wenham, Director of the ARC Centre, said the new record was not directly comparable to the 25 per cent efficiency world record for an individual solar cell set by UNSW last year. However it was an important pointer for the future potential of solar photovoltaic power.
“This latest record involves an expensive combination of cells and the sunlight was focused to produce a much higher intensity than standard sunlight for these measurements. It does show, however, what eventually may be practical,” Professor Wenham said.
ARC Photovoltaics Centre of Excellence
The ARC Photovoltaics Centre of Excellence officially came into being on 13th June 2003. The new Centre is charged with the mission of advancing silicon photovoltaic research and applying these advances to the related field of silicon photonics.
Annual Report of the ARC Centre of Excellence
The Annual Report for the ARC Photovoltaics Centre of Excellence is available by clicking the above link. All of the research activities are detailed in the annual report.
The Centre of Excellence is made up of five research teams dedicated to finding novel ways of improving the efficiency and cost of silicon based photovoltaic and photonic devices.
Buried Contact Group
The Buried-Contact Solar Cell Group aims to develop new solar cell structures and novel process technologies specifically for commercially relevant silicon wafers. The group has a broad spectrum of research and development activities that address the evolving nature of commercial silicon solar cells. The Group’s main activities are focused on developing high-efficiency, thin-wafer Buried-Contact solar cells, developing low-cost processing technologies and related device designs, and transferring BC technology to industrial and technical collaborators.
High Efficiency Group
The high efficiency solar cell group aims to maintain the Centre’s international leadership position in this area and to demonstrate the performance potential of new concepts by showing them at their full capability.
Thin Film Group
The primary aim of the Centre’s thin-film cell group (or “second-generation group”) is to develop polycrystalline silicon (poly-Si) thin-film solar cells on glass, an approach that is widely recognised as being a pathway towards substantially lowering the cost of photovoltaic (PV) solar electricity.
Third Generation Photovoltaics
Third Generation concepts are based on devices than can exceed the theoretical solar conversion efficiency limit for a single energy threshold material.
The Centre’s work in silicon photonics has two main thrusts. The first is to demonstrate silicon light emitters that can be integrated into silicon microelectronic circuits. The second is to investigate the feasibility of innovative schemes for demonstrating the silicon laser. A range of silicon optoelectronic characterisation activities underpin both these programs.
The Centre has established relationships with industry and educational organisations locally and overseas.