A new discovery from a chemist at the University of Texas at Austin may allow photovoltaic solar cells to double their efficiency, thus providing loads more electrical power from regular sunlight.
Not only that, but it’s way cheap. Chemistry professor Xiaoyang Zhu and his team discovered that an organic plastic semiconductor could double the number of electrons harvested out of one photon of sunlight. Yep, plastic.
An issue with regular photovoltaic panels is that much of the energy delivered by sunlight comes in the form of “hot” electrons, which are too high-energy to be converted to electricity in silicon and are instead lost as heat. For that reason, the max insolation-to-electricity efficiency of a silicon solar cell used today is considered to be about 31%. Capturing those hot electrons could boost it to 66%.
Zhu’s process involves absorbing the photon of sunlight in a plastic – in his experiments, pentacene – to produce a dark quantum “shadow state” from which two electrons can be retrieved, instead of just one.
Right now, his experiments use ordinary sunlight, and not focused sunlight, and he’s getting 44% efficiency. That’s a big boost in electricity, and it means it could be done with ordinary rooftop panels.
Breakthroughs in the solar industry seem to be coming fast of late. Just two weeks ago we heard about researcher Douglas Keszlar at Oregon State University in Corvallis, who is studying the photovoltaic potential of fool’s gold– pyrite – and discovered instead that some more ordinary materials could make improved photovoltaics, especially iron silicon sulfide. Once again, the advantage would be that it’s hyperefficient and cheap.
Lewis, the work of Professor Zhu is important. However, the LA Times is rather confused on what pentacene is. Pentacene is an effectively linear molecule containing five fused aromatic or benzene rings. It is a solid at room temperature. As UV light is absorbed, the delocalization of electrons enables a purple color.
I am puzzled per what the author means by the term "plastic." There neither are any intuitive nor obvious changes that would produce an organic polymer (what a plastic is). The editor of the LA Times ought to have had someone knowledgeable review this important article for accuracy/clarity prior to publication.
Someone pointed out that the LA Times somewhat=confused article was from 2011. I ran across it in the course of researching a company that is attempting to commercialize the breakthrough. The company is Natcore (NTCXF). I'm not sure if the stock is undergoing a pump-and-dump right now, so I can't recommend it but some of the press releases are promising.
I like solar power although I don't like the current Administration's propensity to funnel taxpayer money into it in return for campaign contributions, while attacking oil, coal, natural gas, and nuclear power.