New type of solar cell uses an inorganic nanowire structure
April 13, 2011
Researchers from Xiamen University in China and the University of North Carolina at Charlotte have successfully fabricated and tested a new type of solar cell using an inorganic nanowire structure.
The researchers created zinc oxide (ZnO) nanowires with a zinc selenide (ZnSe) coating to form a material structure known as a type-II heterojunction, which has a significantly lower bandgap than either of the original materials. Arrays of the structured nanowires were subsequently able to absorb light from the visible and near-infrared wavelengths.
The nanowires were created by first growing an array of six-sided zinc oxide crystal “wires” from a thin film of the same material, using vapor deposition. The technique created a forest of smooth-sided needle-like zinc oxide crystals with uniform diameters (40 to 80 nanometers) along their length (approximately 1.4 micrometers).
A somewhat rougher zinc selenide shell was then deposited to coat all the wires. Finally, an indium tin oxide (ITO) film was bonded to the zinc selenide coating, and an indium probe was connected to the zinc oxide film, creating contacts for any current generated by the cell.
The researchers showed the photoresponse threshold of the nanowire structure to be 1.6 eV, capable of absorbing light wavelengths from the ultraviolet to the near infrared.
Ref.: Shuping Li and Junyong Kang et al., An all-inorganic type-II heterojunction array with nearly full solar spectral response based on ZnO/ZnSe core/shell nanowires, Journal of Materials Chemistry, March 14, 2011
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Comments (1)
by Katherine MacLean (old science fiction writer and research fan
What’s next? Of this great array of new ways to make solar cells, No heavy investment can go into mass production and mass sales until the investors can be sure the next different way to make solar cells won’t be better and undercut their price and performance and bankrupt their new factory and its stocks. With the standoff of new tech against investment in heavy production of current models–One way to produce and sell solar cells at a profit is to be cheap by converting factories already mass produced other cheaper gadgets to producing solar cells or by encouraging geek techs to convert one to the other. The Japanese started their car empire by converting our garbage tin cans into tiny toy railroad engines and toy sportcars for christmas sales. We need that kind of brains for that kind of speed, before tar-sand oil coal mathane air pollution etc overheats the political tropics to desert and their population dies off. Multiple interlocked deadlines for our new generation of highspeed techs to solve with inventions. As a futurist I see cheap tinted plastic film making electricity and shade for the Sahara and resettling of shaded desert’s farm space by refugee who also farm desert plants made to be edible farms plants by brilliant geek geneticists. Who are right now getting desert plant type deep root systems cross bred into food plants. It can all work out with speed.