spendergast Informed Prostate Cancer Patient: MIT ONE Lab Develop Ultra Efficient, Light, Thin Solar Cells

The MIT team has achieved the thinnest and lightest complete solar cells ever made, they say. To demonstrate just how thin and lightweight the cells are, the researchers draped a working cell on top of a soap bubble, without popping the bubble.

Photo: Joel Jean and Anna Osherov

MIT Researchers Develop Efficient and Thin Solar Cells | NH Voice
MIT researchers at the ONE (Organics and Nanostructured Electronics) Lab have used a common flexible polymer called parylene for the substrate and the overcoating and DBP was used as the primary light-absorbing layer. Parylene is the trade name for a variety of chemical vapor deposited poly(p-xylylene) polymers used as moisture and dielectric barriers. Among them, Parylene C is the most popular due to its combination of barrier properties, cost, and other processing advantages. The process is carried out in a vacuum chamber at room temperature without any solvents that are used in conventional solar-cell manufacturing.
The researchers have affirmed that different materials can be used for the substrate and covering layers. In addition, the team said that they have already been able to develop the thinnest and lightest complete solar cells ever made. In order to prove the same, they draped the cell on top of soap bubble.
The solar cell used in demonstration is efficient owing to its low weight; its power-to-weight ratio is among the highest ever achieved. “It could be so light that you don't even know it's there, on your shirt or on your notebook. These cells could simply be an add-on to existing structures”, affirmed Vladimir Bulovic.

Solar cells as light as a soap bubble | MIT News
The new process is described in a paper [In situ vapor-deposited parylene substrates for ultra-thin, lightweight organic solar cells] by MIT professor Vladimir Bulović, research scientist Annie Wang, and doctoral student Joel Jean, in the April issue of journal Organic Electronics.
Bulović, MIT’s associate dean for innovation and the Fariborz Maseeh (1990) Professor of Emerging Technology, says the key to the new approach is to make the solar cell, the substrate that supports it, and a protective overcoating to shield it from the environment, all in one process. The substrate is made in place and never needs to be handled, cleaned, or removed from the vacuum during fabrication, thus minimizing exposure to dust or other contaminants that could degrade the cell’s performance.
“The innovative step is the realization that you can grow the substrate at the same time as you grow the device,” Bulović says.

In this initial proof-of-concept experiment, the team used a common flexible polymer called parylene as both the substrate and the overcoating, and an organic material called DBP as the primary light-absorbing layer. Parylene is a commercially available plastic coating used widely to protect implanted biomedical devices and printed circuit boards from environmental damage. The entire process takes place in a vacuum chamber at room temperature and without the use of any solvents, unlike conventional solar-cell manufacturing, which requires high temperatures and harsh chemicals. In this case, both the substrate and the solar cell are “grown” using established vapor deposition techniques.