Toward making semitransparent solar cells the size of windows

• In an essential step toward bringing transparent solar cells to home windows, researchers at the University of Michigan have actually created a way to produce their very reliable and semitransparent solar cells.

"In principle, we can currently scale semitransparent organic solar cells to two meters by two meters, which brings our windows much better to fact," stated Stephen Forrest, the Peter A. Franken Distinguished University Professor of Electrical Engineering and corresponding writer of a study released in Joule.

Traditional silicon-based solar cells are totally nontransparent, which works for solar ranches and roofs however would certainly beat the objective of windows. However, organic solar cells, in which the light absorber is a type of plastic, can be transparent.

Organic solar cells have lagged behind their silicon-based relatives for energy-producing objectives because of engineering challenges such as reduced effectiveness and short life-spans, yet current work out of Forrest's lab has attained document efficiencies of 10% and approximated lifetimes of approximately three decades.

So the team has actually transformed its focus to making transparent solar cells manufacturable. A considerable challenge is developing the micron-scale electrical connections in between specific cells that consist of the solar module. Conventional methods that use lasers to pattern the cells can easily harm the organic light absorbers.

Instead, the group created a multistep peel-off pattern method that accomplished micron-scale resolution. They transferred thin films of plastic and formed them into exceptionally thin strips. After that, they set down the organic and steel layers. Next, they peeled off the strips, creating extremely fine electrical interconnections in between the cells.

The group connected eight semitransparent solar cells, each 4 cm x 0.4 cm and divided by 200µm-wide interconnections, to create a solitary 13 cm2 module. The power conversion performance of 7.3% was around 10% less than for the specific solar cells in the module. This tiny performance loss does not boost with the size of the module; hence, similar effectiveness are expected for meter-scale panels as well. With a transparency nearing 50% and a green tint, the cells are suitable for use in commercial windows. Greater transparencies that are likely favored for the residential market are quickly accomplished by this same innovation.

"It is currently time to obtain market involved to turn this technology right into affordable applications," claimed Xinjing Huang, U-M doctoral trainee in applied physics and first writer on the published research study.

Eventually, the flexible solar cell panel will be sandwiched between 2 window panes. The goal for these energy-generating window films is to be about 50% transparent with 10%-15% performance. Forrest thinks this can be accomplished within a pair years.

"The research we are doing is derisking the technology to make sure that suppliers can make the investments required to go into huge scale production," Forrest stated.

The method can also be generalised to various other organic digital gadgets, he claims. And actually, his team is already using it to OLEDs for white lighting.

The University of Michigan has applied for patent defense and is seeking companions to bring the modern technology to market.