Sign in with
Sign up | Sign in

Solar Cells Can be Built Using Any Semiconductor

By - Source: UC Berkeley | B 25 comments

Researchers at the Berkeley Lab and the University of California (UC) Berkeley found that inexpensive semiconductors can be used to create photovoltaic devices via a gate field, as long as a certain geometric shape of the electrode is maintained.

Solar cells could be seeing much more widespread use and application as a result of research results announced by the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. The technology is called screening-engineered field-effect photovoltaics, short SFPV. The approach utilizes the electric field effect as well as a "carefully designed partially screening top electrode" that "lets the gate electric field sufficiently penetrate the electrode and more uniformly modulate the semiconductor carrier concentration and type to induce a p-n junction."

"Our technology requires only electrode and gate deposition, without the need for high-temperature chemical doping, ion implantation, or other expensive or damaging processes," said William Regan, lead author of the study. "The key to our success is the minimal screening of the gate field which is achieved through geometric structuring of the top electrode. This makes it possible for electrical contact to and carrier modulation of the semiconductor to be performed simultaneously."

The Berkeley scientists said that they shaped the electrode contact into narrow fingers using copper oxide in one configuration and, in another configuration, they created a single-layer graphene surface. "With sufficiently narrow fingers, the gate field creates a low electrical resistance inversion layer between the fingers and a potential barrier beneath them," the researchers said. "A uniformly thin top contact allows gate fields to penetrate and deplete/invert the underlying semiconductor. This results in both configurations are high quality p-n junctions."

"Our demonstrations show that a stable, electrically contacted p-n junction can be achieved with nearly any semiconductor and any electrode material through the application of a gate field provided that the electrode is appropriately geometrically structured," Feng Wang, co-author of the study, noted.

 

Contact Us for News Tips, Corrections and Feedback

Display 25 Comments.
This thread is closed for comments
Top Comments
  • 14 Hide
    belardo , July 31, 2012 11:04 AM
    Oil companies will pay to keep this stuff off the market.
  • 11 Hide
    namecnassianer , July 31, 2012 10:52 AM
    Energy from the sky!

    And it's free (almost).

    This is where governments should be spending money, instead of on new landmines that render people asunder.
Other Comments
  • 7 Hide
    Soulmachiklamo , July 31, 2012 9:52 AM
    Good! I hope this leads to more efficient solar panels. At least when their price is compared.
  • 11 Hide
    namecnassianer , July 31, 2012 10:52 AM
    Energy from the sky!

    And it's free (almost).

    This is where governments should be spending money, instead of on new landmines that render people asunder.
  • 5 Hide
    nikorr , July 31, 2012 11:04 AM
    Whats the efficiency?
  • 14 Hide
    belardo , July 31, 2012 11:04 AM
    Oil companies will pay to keep this stuff off the market.
  • 7 Hide
    hardcore_gamer , July 31, 2012 11:16 AM
    We have to stop our dependency on foreign oil asap. Right now, we are indirectly funding terrorist organizations.
  • 1 Hide
    CaedenV , July 31, 2012 11:51 AM
    NikorrWhats the efficiency?

    my thoughts exactly, It would be great to have cheap panels, but unless we can make them near 20% efficient then it would take too much surface area to power the average home. But if it is efficient, and they can get it down the pipe in 5 years when I need to redo my roof then I will be a happy camper :D 
    belardoOil companies will pay to keep this stuff off the market.

    They could try (and have tried for several years), but ultimately there is too much demand for the solar movement on all fronts. Solar (once we get it down to a cheap enough initial investment, and good battery tech) will take over the consumer/home market, and oil will be relegated to 'heavy' uses such as air travel, bulk transit (rails and boats), and military.
    hardcore_gamerWe have to stop our dependency on foreign oil asap. Right now, we are indirectly funding terrorist organizations.

    When things start moving solar it is going to make some huge changes in the world's power structure. Countries like the US will move to solar and natural gas/coal, while many European countries will move to solar and nuclear. 3rd world countries will then be stuck on oil, and desperate oil producing countries will make their lives a living hell.
    Here in the first world we will see huge political shifts moving from the large influence of oil companies and centralized power grids to solar companies and an ever increasingly decentralized power grid which will potentially further the gap between the 'haves' and the 'have nots'. If you can afford your own power cells then you get 'free' power (or at least very cheap power) to do with as you please. If you cannot afford your own power cells, or live in a city where you do not have access to your own power source, then you will be forced to rely on power companies which will be coping with huge losses in business, while still being required to maintain a massive power grid. Hopefully we will find answers to these problems in time, but I think a lot of people overlook many of the potential problems that can occur as we move over to this new tech. As mentioned above, I'll be moving to solar regardless when it comes time to replace the roof.
  • -2 Hide
    CaedenV , July 31, 2012 11:56 AM
    hardcore_gamerWe have to stop our dependency on foreign oil asap. Right now, we are indirectly funding terrorist organizations.

    What happens when a bully is accustomed to taking your lunch money, and you stop giving it to them? Not saying that we should be giving them money; But when we stop (and we will) it will likely cause a lot of problems once they become desperate.
  • -3 Hide
    lamorpa , July 31, 2012 1:43 PM
    belardoOil companies will pay to keep this stuff off the market.

    ...just like the saltwater powered car?

    (conspiracy theorists are always entertaining)
  • -7 Hide
    Adhmuz , July 31, 2012 1:58 PM
    The only issue I have with solar energy is this, what happens when it rains? or its overcast? Yes it's clean, its free, but it takes up a lot of land and at the end of the day the sun goes down, then what. Most free energy is so unreliable that its not feasible to have it power our infrastructure, Yet. It does contribute and help just not enough, and not on a global scale. Hydroelectric and geothermal, this is an area that needs better development, tidal power especially should be looked at more closely. There's massive potential for clean renewable energy, I just don't see it being developed until we run out of fossil fuels and by then the damage will be done and our atmosphere will be so polluted the oil companies will just start selling us the air we breath.
  • -4 Hide
    blood_dew , July 31, 2012 2:45 PM
    Solar gets WAY too much attention. I'm looking forward to next generation nuclear technologies. The grid CANNOT be powered by energy that is only on during the day, when it isn't cloudy. Before you say the Gov't should be spending money on solar look in to the potential alternatives!

    Liquid Fluoride Thorium Reactors would be:
    Cheaper, always on, far safer than today's Light Water Reactors, run on an energy source that we would literally NEVER run out of, and be able to reprocess transuranic waste from todays nuclear plants. They can also be built to desalinate water. All without producing ANY carbon. Also because it is thorium instead of enriched uranium you are literally looking at ENDING the threat of nuclear proliferation.
  • 0 Hide
    freggo , July 31, 2012 2:48 PM
    AdhmuzThe only issue I have with solar energy is this, what happens when it rains? or its overcast? Yes it's clean, its free, but it takes up a lot of land and at the end of the day the sun goes down, then what.


    You combine a solar power station with some form of energy storage of course.
    Can be anything from batteries to molten salt to water reservoirs etc.
    Personally I'd use excess electricity to take humidity from the air, split it into Hydrogen/Oxygen and store the hydrogen. You can then later 'burn' the hydrogen as needed to produce electricity again -and get clean water as a 'waste' product.

  • 1 Hide
    lamorpa , July 31, 2012 3:11 PM
    freggoYou combine a solar power station with some form of energy storage of course.Can be anything from...

    Do you forget about the environment load the system you propose would create from development, manufacture, transport, installation, maintenance, obsolescence, and disposal/recycling? It's not necessarily less than current energy production methods.
  • -3 Hide
    HeadScratcher7 , July 31, 2012 3:47 PM
    For those that still think nuclear is the solution, remember that global warming isn't just about the greenhouse gases we put in the air but also about the heat we put into the ground and water - and nuclear outputs 4x as much heat as other power generation processing (can't remember where I read that.) Besides, there are plenty of ways to store energy: better batteries, separate water, pump water up hill, gravel filled silos heated/cooled with argon gas, glass/steel structures that soak up heat and produce artificial thermal winds, etc.
    Solar, wind, geothermal, and tidal forces are everywhere - we just have to figure out how to use them better. I once heard that there is enough geothermal energy in California to power the ENTIRE state and yet its almost entirely unused - likely due to the influence of oil and energy producing companies.
  • 1 Hide
    lamorpa , July 31, 2012 4:02 PM
    HeadScratcher7For those that still think nuclear is the solution, remember that global warming isn't just about the greenhouse gases we put in the air but also about the heat we put into the ground and water...

    and make sure to forget the development, construction, maintenance, environmental disruption, etc. of these '0 energy' facilities (and storage facilities) is huge.

    Oh, and by the way, you heard wrong about the nuclear heat output and the CA geothermal energy. Both statements are nonsense.
  • 0 Hide
    JohnnyLucky , July 31, 2012 4:05 PM
    Interesting article and quite a variety of comments. I wonder what motivation and incentives would speed up research and development of all alternative fuels. I certainly hope it is not running out of fossil fuels.
  • 2 Hide
    Bloob , July 31, 2012 4:14 PM
    freggoYou combine a solar power station with some form of energy storage of course.Can be anything from batteries to molten salt to water reservoirs etc.Personally I'd use excess electricity to take humidity from the air, split it into Hydrogen/Oxygen and store the hydrogen. You can then later 'burn' the hydrogen as needed to produce electricity again -and get clean water as a 'waste' product.

    You'd lose 50% of the energy when splitting water, not to mention it's gathering, pumbing, and the usually low efficiency of the solar panels themselves. Even so I am pro solar; as long as it becomes widespread enough, there'll be less problems with cloudy skies. That said, I am pro nuclear as well, as a reliable and efficient supporting structure is always needed.
  • 3 Hide
    Houndsteeth , July 31, 2012 6:27 PM
    Actually, if they can make it cheap enough that it can be embedded in roofing material and not significantly increase the cost (say, about an additional 10-15%), then I could see a bright future, especially in states like Texas, New Mexico and Arizona, where sunny days are extremely plentiful.

    And these PVCs don't have to supply the whole amount of electricity needed by the house. Even 50% of the energy use would be enough to provide relief to most grids, especially in hot summer months when air conditioning uses the most energy. The good news is on those days when you need AC the most, the sun is pumping out a lot of energy to the solar cells, too.
  • 0 Hide
    eddieroolz , July 31, 2012 6:42 PM
    Just a while ago, Panasonic also managed to build a solar cell that is almost as efficient as photosynthesis. That's amazing.
  • 1 Hide
    rosen380 , July 31, 2012 6:52 PM
    "my thoughts exactly, It would be great to have cheap panels, but unless we can make them near 20% efficient then it would take too much surface area to power the average home."

    But what if your options were low efficiency panels that can provide 20% of your needs and cost $2000 installed yourself vs more efficient panels that provide 100% of the power you need but cost $25k.

    Figuring 4% increases in energy costs, $200 per month current costs and static use, I come up with the break-even being just under 4 years for the cheap system versus over almost nine years for the expensive system. Given the assumptions I made, the two cross paths at about 10 years, so if you expect to replace the system before then, you are probably better off with the cheap one. If you are using the system for over a decade, then go expensive.

    though there is also the value of having the difference invested- That $23K you didn't spend up front, invested, making only 2% would push the break-even for the two systems to 12 years.
  • 0 Hide
    palladin9479 , August 1, 2012 1:27 AM
    Some pretty erroneous assumptions by people watching far too much TV. Solar / Wind are not "the future", they can't provide anywhere near enough power to make a dent in our consumption, a consumption that will only go up. That's not saying their bad, because their not. They make the most sense when you can get them for "free", like rooftops on houses and turbines on hill tops. In those situations your not giving up anything significant and thus their energy gain can be used to supplement energy usage. Also their both extremely inadequate to base load, work for peak or swing if stored but you can forget base load.

    For long term base load power the only options are nuclear and geo-thermal. Contrary to what the greens will say, nukes are actually extremely environmentally friendly. Biggest hurdle is getting away from Gen I / II PWR / BWR / LWBR design's and moving onto Gen IV MSR / LFTRs. ALL our news today, every scrap of "bad" info is from the old Gen I designs. The environmentalists have been so successful in shutting down nuke designs that China and other countries are actually ahead of the USA in reactor technology. Go figure China will have safer fission plants then the USA soon.

    Geo-thermal would be awesome, horizontal drilling has made it easier but we're not quite at the point where their cheap enough to use. Once we can drill and build a heat exchanger at 10km down then Geo-thermal can take off.

    And of course you have the holy grail of power, Nuclear Fusion. There have been several design's being testing and worked on, one I like to follow is the poly-well concept of using electrostatics to do the confinement. Plenty of fusion fuel in the dirt under everyone's feet.
Display more comments