- Category: Technology
10 Aug 2012
- Published on Friday, 10 August 2012 09:56
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Chemists at Brown University have developed a simpler and easier manufacturing process for transparent, conductive thin films that can be used as protective layer for solar cells.
Most solar panels have an outer layer of transparent protective material over the actual solar cells to protect the semiconductor wafers from the wear and tear of being exposed to the elements.
Traditionally, the protective layer has been glass. But with the recent move toward making solar devices smaller and of lighter weight, glass has fallen out of favor.
A thin film of material called indium tin oxide is being considered as a better alternative for the protective layer of solar panels. It also has applications for touch-screen technologies.
The Brown chemists produce their indium tin oxide films using a chemical solution that can be easily controlled to create films of varying thickness and tin content.
They made conductive indium tin oxide films 146 billionths of a meter thick that allowed 93 percent of light to pass through. In several experiments, they showed that by varying the thickness and the tin content (between 5 and 10 percent was best), they could vary the transparency and resistance to find the best combination.
The chemists synthesize nanoscale ITO crystals into a solution. To make the film they simply dripped the solution onto a glass plate, followed by rapid spinning in a common manufacturing process called spin casting. After the film was spin cast, they baked or annealed the coated plates.
Since creating the film uses little materials and simple and established manufacturing processes, the indium tin oxide films produced are more cost effective then other methods.
The researchers are going to continue their work with the nanoscale indium tin oxide crystal solutions they used for the current batch of thin films. They believe that they might be able to devise a way to eventually manufacture highly-conductive, transparent indium tin oxide thin films using inkjet or roll-to-roll printing. – EcoSeed Staff