David Kirkpatrick

July 16, 2010

Solar plus nanotech equals lower cost cells

I always love covering news that combines solar and nanotechnology, particularly when the combo leads to lower costs for solar power. I’ve previously blogged about nanopillars leading increased solar efficiency.

From the first link:

A material with a novel nanostructure developed by researchers at the University of California, Berkeley could lead to lower-cost solar cells and light detectors. It absorbs light just as well as commercial thin-film solar cells but uses much less semiconductor material.

The new material consists of an array of nanopillars that are narrow at the top and thicker at the bottom. The narrow tops allow light to penetrate the array without reflecting off. The thicker bottom absorbs light so that it can be converted into electricity. The design absorbs 99 percent of visible light, compared to the 85 percent absorbed by an earlier design in which the nanopillars were the same thickness along their entire length. An ordinary flat film of the material would absorb only 15 percent of the light.

Thick and thin: A scanning electron microscope image shows dual-diameter light-trapping germanium nanopillars.

Credit: Ali Javey, UC Berkeley

February 17, 2010

Efficient thin-film solar through nanotech

Filed under: Business, Science — Tags: , , , , , — David Kirkpatrick @ 2:54 pm

A nanotechnology design improves the efficiency of thin-film solar cells. An important breakthrough in working to commercially viable solar power because thin-film cells are cheaper than photovoltaics, but efficiency has been an issue. The two key elements  in making solar energy widespread and a credible challenger to petroleum-based energy are lower costs (both in installation and maintenance) and higher efficiencies. Anything that works to combine those two elements is a step in the right direction.

I just love blog posts that combine nanotechnology and solar power.

From the link:

Thin-film solar cells are less expensive than traditional photovoltaics sliced from wafers, but they’re not as efficient at converting the energy in sunlight into electricity. Now a Newton, MA-based startup is developing a nanostructured design that overcomes one of the main constraints on the performance of thin-film solar cells. Solasta fabricates on arrays of nanopillars, rather than flat areas, boosting the efficiency of amorphous silicon solar cells to about 10 percent–still less than crystalline silicon panels, but more than the thin-film amorphous silicon panels on the market today. The company says that the design won’t require new equipment or materials and that it will license its technology to amorphous-silicon manufacturers at the end of this year.

Pillar power: This microscope image shows the layers of a solar cell built on a nanopillar substrate. The core of each pillar is coated first with metal, then amorphous silicon, and then a transparent conductive oxide.

Credit: Solasta