A little while ago I reported on Samsung’s acquisition of Liquavista. A few days ago there was an item reporting that Samsung have entered into an agreement to license the quantum dot technology owned by Evident. This agreement grants Samsung worldwide access to Evident’s patent portfolio for all products related to quantum dot LEDs from manufacture of the quantum dot nanomaterials to final LED production.
Quantum dots are nanometer-sized semiconductor crystals that have great commercial promise in electronic applications from solar energy conversion to thermoelectrics to LEDs. Evident was the first company in the world to commercialize quantum dot LEDs with products launched in 2007.
A quick overview of the Evident quantum dot technology can be had by viewing their patent portfolio. Using Boliven.com I searched for granted patents with Evident as an assignee and quantum dots in the claims. This showed at least 7 patents with the two most cited shown below:
1. Fabry-perot opitcal switch having a saturable absorber
U.S. Patent US6697548 | Filed: 06/25/2001 | Issued: 02/24/2004 Cited: 7 Times
Assignee(s): Evident Technologies | Inventor(s): Michael LoCascio + 3
A Fabry-Perot optical switch includes a saturable absorber surrounded by a pair of mirrors. Coupled to the saturable absorber is an input waveguide, an output waveguide, and a control beam waveguide. In the absence of light input to the control beam waveguide, the saturable absorber prevents an input signal on the input waveguide from passing through and being output on the output waveguide, thus placing the switch in an “off” state. In the presence of light input to the control beam waveguide and incident on the saturable absorber, the saturable absorber allows the input signal to pass through and be output on the output waveguide, or be reflected and output on the output waveguide, thus placing the switch in an “on” state.
2. Optical dispersion compensator
U.S. Patent US6611640 | Filed: 02/14/2001 | Issued: 08/26/2003 Cited: 7 Times
Assignee(s): Evident Technologies | Inventor(s): Michael LoCasclo + 2
An optical dispersion compensator includes a saturable absorber. Coupled to the saturable absorber is a pre-amplifier and a post-amplifier. The saturable absorber compresses optical pulse signals based upon the amplitude envelope of the optical pulse in order to prevent optical dispersion.
What will Samsung get from this? Well, as these patents demonstrate quantum dots are particularly significant for optical applications. Samsung are no doubt interested in building displays using quantum dots to provide superior LEDs because they emit light in very specific gaussian distributions. This means that a display that more accurately renders the colors that the human eye can perceive can be built. Quantum dots also require very little power since they are not color filtered and this will benefit future display technology. Displays that intrinsically produce the red green and blue pixels (rather than using colour filters over white light) can be more efficient, since more of the light produced reaches the eye.
Evident Technologies Inc. have a number of patent applications in the pipeline which refer to LEDs made with quantum dots. For example US20080246017: Light Emitting Device Having Semiconductor Nanocrystal Complexes. The abstract for this patent reads:
Light-emitting devices are provided that incorporate one or more underlying LED chips or other light sources and a layer having one or more populations of nanoparticles disposed over the light source. The nanoparticles may absorb some light emitted by the underlying source, and re-emit light at a different level. By varying the type and relative concentration of nanoparticles, different emission spectra may be achieved. White light and specialty-color emission may be achieved. Devices also may include multiple LED chips, with nanoparticles disposed over one or more underlying chips in an array.