Grating-based pixel-color filters convert wasted LCD light to electricity

photovoltaic_filters2
Cyan, magenta, and yellow filters for liquid-crystal displays are photovoltaic, harvesting wasted energy. (Images: Jay Guo)

 

Ann Arbor, MI--A new type of color filter for pixels in liquid-crystal displays (LCDs) has been developed by researchers at the University of Michigan: in addition to providing a pixel's hue, the filter is a photovoltaic cell that can harvest some of the wasted light from the display for useful energy.1 You may ask, Does this make sense? In fact, yes it does -- in a typical LCD less than 8% of the backlighting reaches the viewer's eyes, which is partially due to the absorbing color filters. Even a rudimentary energy-harvesting ability would help wall-plug efficiency.


The photovoltaic filter, developed by Jay Guo and his group, converts about 2% of the light that would otherwise be wasted to power. This could add up to a significant amount in small electronics, says Guo.

The researchers created the new filter by adding organic semiconductor photovoltaic cells to an ultrathin color filter, similar to what Guo's lab had created more than a year ago. That filter is composed of nano structured gratings that act as resonators for light of a particular color. The color depends on the grating period.

At 200 nm thick, the new filter is 100 times thinner than traditional colorant-based filters, a characteristic that could be attractive for use in future ultrathin color displays. The technology could also potentially be used in larger displays to make energy-harvesting billboards or decorative solar panels.

The University of Michigan is pursuing patent protection for the intellectual property.

Source: http://ns.umich.edu/htdocs/releases/story.php?id=8599


REFERENCE:

1. Hui Joon Park et al., ACS Nano, 2011, 5 (9), p. 7055.




50 YEARS OF SOLID-STATE LASERS


A long way from the ruby laser

Most Popular Articles

Webcasts

Ray Optics Simulations with COMSOL Multiphysics

The Ray Optics Module can be used to simulate electromagnetic wave propagation when the wavelength is much smaller than the smallest geometric entity in the ...

Multichannel Spectroscopy: Technology and Applications

This webcast, sponsored by Hamamatsu, highlights some of the photonic technology used in spectroscopy, and the resulting applications.

Handheld Spectrometers

Spectroscopy is a powerful and versatile tool that traditionally often required a large and bulky instrument. The combination of compact optics and modern pa...

Fracking, climate change, and lasers:  new tools to reduce fugitive methane emissions

This webcast, sponsored by Hamamatsu Corporation, covers recent developments and field deployments of compact quantum-cascade-laser (QCL)-based methane senso...
White Papers

Narrow-line fiber-coupled modules for DPAL pumping

A new series of fiber coupled diode laser modules optimized for DPAL pumping is presented, featur...

Accurate LED Source Modeling Using TracePro

Modern optical modeling programs allow product design engineers to create, analyze, and optimize ...

Optical Isolators Improve Engraving Performance of Pulsed Fiber Lasers

The deleterious effects of back reflections on pulsed fiber lasers used in marking and engraving ...
Technical Digests

ADHESIVES, SEALANTS, AND COATINGS: Solutions for optical technologies

A vast array of optical systems of various types and degrees of complexity require the use of adh...

WAVELENGTH-SWEPT LASERS: Dispersion-tuned fiber laser sweeps over a 140 nm range for OCT

By eliminating the use of mechanical tunable filters and instead tuning by intensity-modulation i...

Keeping pace with developments in photonic materials research

For demanding or custom spectroscopy solutions, care must be taken in selecting and integrating a...

HIGH-POWER FIBER LASERS: Working in the kilowatt regime

High-power materials-processing fiber lasers are available in an increasing variety of forms, as ...

Click here to have your products listed in the Laser Focus World Buyers Guide.
Social Activity
  •  
  •  
  •  
  •  
  •  
Copyright © 2007-2014. PennWell Corporation, Tulsa, OK. All Rights Reserved.PRIVACY POLICY | TERMS AND CONDITIONS