Scientists develop spray-on solar panels
By Stephanie Stohr, G-Online, 30 Jan. 2009
Source: G-Online.com
http://www.gmagazine.com.au/news/1193/scientists-develop-spray-solar-panels
A new type of spray-on solar panel will make the cells cheaper and production more efficient. Taking a leaf from the beauty industry, scientists have devised a way to make solar panels cheaper and more efficient – by spraying them on. Researchers from the Australian National University (ANU), solar company Spark Solar Australia, and Finnish materials company Braggone Oy are collaborating on a three-year project that could transform the production of solar cells. “I think it has a big chance of success,” said Keith McIntosh, lead researcher from the ANU, “It’s an exciting possibility.”
Solar cells are typically made of silicon coated with a thin layer of silicon nitrate – which is used as an antireflective agent to increase cell efficiency. However, these types of cells are costly to produce because they are made in a vacuum. The plasma form of hydrogen, another expensive material used in solar cell production, is used to capture the energy from the sun’s rays.
The new method developed by Braggone Oy uses a spray-on hydrogen film and spray-on anti-reflective film. Instead of the need for plasma and a vacuum, the cells simply travel along a conveyor belt where the films are sprayed on. “The cells will be the same quality, but much cheaper,” McIntosh said.
Testing of the process is now taking place at the ANU, and the technology should be available toward the end of 2011. “About $5 million will be saved per medium-sized factory,” McIntosh said. “These savings should be passed down to the consumer in a couple of years when demand for solar panels increases.” Besides the price advantage, the project aims to increase cell efficiency too. Presently, solar cells on the market range from 5 to 24 per cent efficiency.
Most of the cells energy is lost at its surface where the material is roughened. This is to increase the surface area that can absorb solar energy. However, roughening the material also disrupts the cell’s crystalline structure in the process. “We want to roughen the surface in several different ways to study the different properties of each. Then we can find the best and most efficient surface,” said Klaus Weber, also from the ANU.
Once an optimal surface is found, the cost of the cells would remain the same, but their efficiency and power would be greater, he said. “What we are trying to get out of it is new ideas and processes to improve the efficiency of solar power,” he added. “If you can get the same efficiency as vacuums with this spray-on technology that’s great; it will make the process a lot cheaper,” said engineer Alistair Sproul from the University of New South Wales in Sydney, Australia. “All of this is a good step in the right direction.”