Scientists at Nanyang Technical University (NTU) and A*STAR Institute of Microelectronics (IME) have developed a thin film silicon solar cell using nanotechnology. The resulting solar cells are significantly cheaper than other thin film solar cells and produce almost as much electricity as traditional silicon solar cells.
Both NTU and IME are working together to create solar cells that cost half of the cost of traditional solar cells but with much better efficiency than other thin film solar cells. The research institutes want more people to have access to solar power. Reducing the cost while keeping efficiencies high is key .
Rather than using the more expensive high grade silicon, low cost amorphous silicon was used. The problem with amorphous silicon is that it isn’t capable of capturing much solar energy.
To create the efficiencies needed, the scientists used nanotechnology to create nanostructures – “which [are] thousands of times smaller than human hair” – on the surface of the silicon to add texture. This is the same concept behind NREL’s Sol-optic Fusion technology. NREL’s Fusion technology creates nanostructures on a thin transparent plastic overlay. The overlay can be placed over existing solar panels or added in production. These nanostructures improve the power conversion efficiencies (PCE) of the solar cells increasing the “energy output.”
The new NTU-A*STAR nano-structured solar cells can produce a current of (34.3mA/cm2) – a world record for a silicon solar cell of its kind.
The resulting electricity current output is close to those of traditional cells (40mA/cm2). Conventional thin film solar cells usually produce about half of the current that traditional cells produce.
The scientists plan to continue working on such areas as “fill factor” and “open circuit voltage” to continue improving the PCE of thin film silicon solar cells in order to reach that of traditional silicon solar cells. Plasmonics, another “light trapping strategy” is also being explored.
NTU and IME have already developed thin film solar cells that are cheaper and more efficient than other thin film solar solutions. That being said, solar efficiencies are continuing to climb in both traditional and thin film solar cells through the use of Liquid Phase Deposition (LPD), use of dyes, nanoplasmodic solar cells, and transparent transistor technology.
Over the past four years several different methods of creating thin film solar cells have been developed. The claim of all of them is that they will be cheaper than traditional solar cells and will be able to provide good PCE. The trick is getting the thin film solar technology out of the lab and into production.
Let’s see how quickly this technology can make it to market before yet a new and better method of improving solar cells is developed.
Above photo: Final installation and layout of Uni-Solar Ovonic’s thin Film Flexible Solar PV panels by Ken Fields.