While battery life of portable electronics has improved substantially, LCD screens found in most mobile phones and laptops, which require backlighting to provide crisp bright images, are power-sapping.
Researchers at University California Los Angeles (UCLA) have developed a new technology that could solve the problem. The team, at the university's Henry Samueli School of Engineering and Applied Science, has designed organic photovoltaic (OPV) polarisers that can be built into LCD screens, to harvest and recycle energy.
The polariser system works by converting ambient light, sunlight and the device's own backlight into electricity.
Yang Yang, a professor of materials science at UCLA Engineering and principal investigator on the research, comments: 'I believe this is a game-changer invention to improve the efficiency of LCD displays. In addition, these polarisers can also be used as regular solar cells to harvest indoor or outdoor light.'
Lighting displays
LCDs, the mostly widely used electronic display technology - found in smartphones, television screens, computer monitors, laptops and tablets computers - work by using two polarised sheets that let only a certain amount of a device's backlight pass through. Tiny liquid crystal molecules are sandwiched between the two polarisers and these crystals can be switched by tiny transistors to act as light valves. Manipulating each light valve, or pixel, lets a certain amount of the backlight escape; millions of pixels are combined to create images on LCDs.
The polarising OPV cell demonstrated by Professor Yang's research group can potentially harvest 75% of the wasted photons from LCD backlights and turn them back into electricity.
The UCLA Engineering team's energy harvesting OPV polariser for LCDs can potentially enhance the function of LCDs by working simultaneously as a polariser, a PV device and an ambient light or sunlight PV panel.
Rui Zhu, a postdoctoral researcher at UCLA Engineering, adds: 'Our coating method is simple, and it can be applied in the future in large-area manufacturing processes.'
The next issue of +Plastic Electronics magazine is an energy harvesting special, with a series of articles on the latest technologies and emerging markets for printed and organic solar, and other energy harvesting technologies.
To sign up for your copy immediately, click the link below, contact publications@pira-international.com or visit our subscriptions page.
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University California Los Angeles
UCLA researchers have created a polariser system that combines with LCD displays to convert ambient light, sunlight and the device’s own backlight into electricity
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Dye solar firm launches energy harvesting products with Texas Instruments
Welsh dye-sensitised solar cell firm G24 Innovations is launching a nano-power energy harvesting product range in a strategic development agreement with semiconductor firm Texas Instruments
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