Solar Breakthrough: Better Crystals, "Oven-Baked" and Painted On
Barring huge subsidies, bringing solar energy to the masses -- from your home to your cell phone -- requires a major drop in the cost of the technology. Treehugger has reported on many advances. Last week, a group of researchers in Australia and China announced they had moved one step closer to the "holy grail of cost-effective solar energy."
According to Professor Max Lu of the University of Queensland, Australia, the team has grown "the world's first titanium oxide single crystals with large amounts of reactive surfaces, something that was predicted as almost impossible." Here's the deal: titanium oxide -- a plentiful, renewable and non-toxic mineral often found in white paint -- is known for its ability to absorb UV light and produce electrons that can break down compounds on its surface. That makes it useful in self-cleaning windows and "pollution-eating" concrete. It can also be used in low-cost and low-efficiency solar cells, also known as Gratzel cells. Up until now, the challenge, tackled by coating titanium oxide in dyeshas been to make the stuff efficient over a large surface area, so the material can both absorb ample light and conduct electricity well. But growing more reactive titanium oxide cells could indeed be a breakthrough. Says Lu:
The researchers also say the technology could be used to split hydrogen from water to create energy and to decontaminate water. While it may be a decade before the technology can be used in solar cells, says Lu, the decontaminating applications may be five years away.
"The beauty of our technique is that it is very simple and cheap to make such materials at mild conditions. Now that the research has elucidated the conditions required, the method is like cooking in an oven and the crystals can be applied like paints."
Similar research into low-cost disruptive solar technologies last year -- at the NJ Institute of Technology, at Massey University, and especially at the University of Notre Dame -- also relies on nanostructures to create high efficiency solar cells. Using a readily available compound like titanium oxide instead of silicon in solar cells may not only prove cheaper and more efficient, but, potentially much more sustainable too.
What is also worth noting is the origin of some of this research: China. Cheap solar wouldn't just help bring down pollution over some of the world's most polluted cities, but would help bolster China's determination to leapfrog the US and Europe in sustainable technologies, in a kind of green tech war that can only help everyone.