In addition to being suitable for installation in stationary modules, solar cells also can be used with mobile devices, Lemp believes. Thin-film technology is the best option here, because cells produced with it are quite light and also flexible. Merck also offers interesting product concepts for such technology as well. The key task is to optimize and align cell output with the electricity consumption of the device in question. “I think it would make perfect sense to use solar cells in mobile devices, to supplement conventional batteries,” says Lemp. Merck’s job in this regard is to develop systems that will generate more watts per euro. This means the future of electricity for mobile devices lies in hybrid solutions that rely on intelligent power management concepts, with batteries and solar cells operating in tandem.

Apple has recognized the potential here, which is why it recently registered a patent for integrating solar cells into its devices. It was actually years ago, at an Apple Macworld trade fair, that Steve Jobs said: “Future generations of iPhones, iPods, and MacBooks will run with the help of solar cells that charge batteries when exposed to light.” As always, Apple is not prepared to sacrifice its pioneering designs to achieve its goals, which is why the company plans to install solar cells directly into the MacBook screen, for example. One benefit of this setup is that it will allow the solar panels embedded behind the LCD display to also absorb the ambient light generated by the screen illumination. This would be truly sensational, representing a completely new concept. Insiders also believe Apple engineers will install solar cells on the back side of the iPhone to provide an additional power source.

Samsung is already further ahead in this regard: The South Korean company’s “Blue Earth” cell phone is a solar powered device that’s scheduled to hit the market before the year is out. The touch screen phone has solar cells integrated into the back. According to Samsung, for every one and one-half hours that the cells are exposed to the sun, the user will be able to telephone for a half hour. Fully charging the battery requires 14 hours of exposure to an intensive source of light.

isishape® also is playing an important role in the structuring and manufacturing of displays and touch panels. When producing the latter, it is important to precisely structure only the correct layer of a multi-layer system, to ensure that the screen functions properly. In some cases, these processes require working at the nanometer level — and such precision work is supported and simplified by isishape®.

Seven years ago, the Fraunhofer Institute for Solar Energy Systems (ISE) demonstrated the efficiencies that future solar cells would achieve by presenting a completely energy-autonomous palmtop that the institute’s researchers had equipped with a high-performance solar cell. Even artificial light provided the palmtop with sufficient power. The high performance achieved with direct sunlight was a result of the palmtop’s special design, which featured 14 individual cells made of monocrystalline silicon that were placed atop one another like roof shingles, delivering efficiency of more than 20 percent. Today, researchers at ISE achieve efficiencies in excess of 40 percent for the conversion of sunlight into electricity. In the corresponding units, sunlight is concentrated 454-fold onto a little multi-junction solar cell that measures five square millimeters and is made from the semiconductors gallium indium phosphide, gallium indium arsenide, and germanium. But with costs as high as €1,500 per watt of electricity produced, such cells are far too expensive for commercial applications. Conventional silicon solar cells, by contrast, produce one watt of electricity for between three and ten euros.

Lemp, in any case, is convinced there is a bright future for solar cells: “Production of solar cells is expected to once again begin expanding at a high double-digit rate in 2010 — it’s really a booming industrial sector.”