Smart windows convert light to energy

Highlights in Chemical Science ^ | 21 October 2009 | Fay Nolan-Neylan

[neverdem]

Increasing energy demands and concerns about global warming mean that the sun is an important inexhaustible and clean energy source. Dye sensitised solar cells (DSSCs) have proved to be a highly efficient and low-cost option for conversion of sunlight to energy. 

Ruthenium dye photosensitisers have given the highest power conversion efficiency in the past but they are not very environmentally friendly and supply is limited, explains Eric Diau at the National Chiao Tung University, Hsinchu, Taiwan. Diau and his team took inspiration from nature by developing a dye based on porphyrin - a component of chlorophyll, which gives plants their green colour and allows them to convert sunlight into energy. They also replaced ruthenium with zinc, which is more abundant and costs less.  

An efficient artificial porphyrin dye is used to harvest solar energy in an organic photovoltaic device

A light scattering layer is often added to a DSSC to improve the efficiency of the device. But Diau's group found that their porphyrin dye performed better than a ruthenium dye in devices without adding a scattering layer. This also made the device see-through meaning it could be integrated into windows in the buildings of the future, explains Diau.

Emilio Palomares from the Institute of Chemical Research of Catalonia, Tarragona, Spain, says this represents 'a

"a step further on the long-standing research into bio-inspired artificial leaves for photovoltaic applications"
- Emilio Palomares, Institute of Chemical Research of Catalonia, Tarragona, Spain

step further on the long-standing research into bio-inspired artificial leaves for photovoltaic applications'. He adds that 'the high efficiency achieved using fully transparent devices makes the dye suitable for applications in smart windows where people can see through, while the window acts as an active light-to-energy conversion system.' 

Diau says that this type of light-weight, see-through and colourful DSSC could be very useful in the building industry. However, he sees some challenges ahead before it is commercialised: solar power conversion efficiency and the stability of the devices need to be improved, he says. 

Link to journal article

Design and characterization of highly efficient porphyrin sensitizers for green see-through dye-sensitized solar cells
Hsueh-Pei Lu, Chi-Lun Mai, Chen-Yuan Tsia, Shun-Ju Hsu, Chou-Pou Hsieh, Chien-Lan Chiu, Chen-Yu Yeh and Eric Wei-Guang Diau, Phys. Chem. Chem. Phys., 2009
DOI: 10.1039/b917271h

Also of interest

Instant insight: Nanohighway to solar cells

Hiroshi Imahori discusses electrophoresis as a means to make molecular highways for organic solar cells.

Lateral thinking for dye-sensitised solar cells

A new way of anchoring dyes in organic solar cells improves their performance

The artificial leaf

Using sunlight to split water molecules and form hydrogen fuel is one of the most promising tactics for kicking our carbon habit. Hayley Birch examines the options

[neverdem]

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[Berlin_Freeper]

redneck light house

[Bellflower]

To read later.

[SunkenCiv]

Thanks neverdem.

Trapped light rattles its cage
Nature News | 18 October 2009 | Zeeya Merali
Posted on 10/19/2009 12:32:56 AM PDT by neverdem
http://www.freerepublic.com/focus/news/2365556/posts