Navigation Links
Dual-color lasers could lead to cheap and efficient LED lighting
Date:5/2/2013

A new semiconductor device capable of emitting two distinct colours has been created by a group of researchers in the US, potentially opening up the possibility of using light emitting diodes (LEDs) universally for cheap and efficient lighting.

The proof-of-concept device, which has been presented today, 3 May, in IOP Publishing's journal Semiconductor Science and Technology, takes advantage of the latest nano-scale materials and processes to emit green and red light separated by a wavelength of 97 nanometresa significantly larger bandwidth than a traditional semiconductor.

Furthermore, the device is much more energy efficient than traditional LEDs as the colours are emitted as lasers, meaning they emit a very sharp and specific spectral linenarrower than a fraction of a nanometrecompared to LEDs which emit colours in a broad bandwidth.

One of the main properties of semiconductors is that they emit light in a certain wavelength range, which has resulted in their widespread use in LEDs. The wavelength range in which a given semiconductor can emit lightalso known as its bandwidthis typically limited in the range of just tens of nanometres. For many applications such as lighting and illumination, the wavelength range needs to be over the entire visible spectrum and thus have a bandwidth of 300 nm.

Single semiconductor devices cannot emit across the entire visible spectrum and therefore need to be 'put' together to form a collection that can cover the entire range. This is very expensive and is, to a large extent, the reason why semiconductor LEDs are not yet used universally for lighting.

In this study, the researchers, from Arizona State University, used a process known as chemical vapour deposition to create a 41 micrometer-long nanosheet made from Cadmium Sulphide and Cadmium Selenide powders, using silicon as a substrate.

Lead author of the study, Professor Cun-Zheng Ning, said: "Semiconductors are traditionally 'grown' together layer-by- layer, on an atom-scale, using the so-called epitaxial growth of crystals. Since different semiconductor crystals typically have different lattice constants, layer-by-layer growth of different semiconductors will cause defects, stress, and ultimately bad crystals, killing light emission properties."

It is because of this that current LEDs cannot have different semiconductors within them to generate red, green and blue colours for lighting.

However, recent developments in the field of nanotechnology mean that structures such as nanowires, nanobelts and nanosheets can be grown to tolerate much larger mismatches of lattice structures, and thus allow very different semiconductors to grow together without too many defects.

"Multi-colour light emission from a single nanowire or nanobelt has been realized in the past but what is important in our paper is that we realized lasers at two distinct colours. To physically 'put' together several lasers of different colors is too costly to be useful and thus our proof-of concept experiment becomes interesting and potentially important technologically.

"In addition to being used for solid state lighting and full color displays, such technology can also be used as light sources for fluorescence bio and chemical detection," continued Professor Ning.


'/>"/>

Contact: Michael Bishop
michael.bishop@iop.org
01-179-301-032
Institute of Physics
Source:Eurekalert

Related biology technology :

1. New method for enhancing thermal conductivity could cool computer chips, lasers and other devices
2. UCSB Physicists mix 2 lasers to create light at many frequencies
3. CU-Boulder physicists use ultrafast lasers to create first tabletop X-ray device
4. SPIE co-sponsors ICTP Winter College on lasers for science, medicine, and industry
5. Breaking the final barrier: Room-temperature electrically powered nanolasers
6. Microfabrication breakthrough could set piezoelectric material applications in motion
7. Pitt discoveries in quantum physics could change face of technology
8. Nanoparticle electrode for batteries could make grid-scale power storage feasible
9. New magnetic-field-sensitive alloy could find use in novel micromechanical devices
10. Low-cost paper-based wireless sensor could help detect explosive devices
11. Discovery of a dark state could mean a brighter future for solar energy
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/3/2016)... Westminster, CO (PRWEB) , ... May 03, 2016 ... ... analysis , announced the addition of Dr. Nancy Gillett to its Board of ... last position, she served as Corporate Executive Vice President and Chief Scientific Officer. ...
(Date:5/3/2016)... (PRWEB) , ... May 03, 2016 , ... According to ... , for definitive prostate cancer treatment, patients traditionally had two main treatment options: surgery ... plan would be made. , New technology has enabled doctors to administer higher ...
(Date:5/2/2016)... , ... May 02, 2016 , ... ... report on the pre-launch success of their revolutionary, veterinarian-designed product for indoor cats. ... stalk, trap, and play with their food the way nature intended. NoBowls make ...
(Date:4/29/2016)... ... 2016 , ... During a two day program for start-up ... CereScan’s CEO, John Kelley, joined other Denver business leaders in providing business basics ... Denver area business community, shared his top fundamental learnings in building an effective, ...
Breaking Biology Technology:
(Date:3/21/2016)... WAKEFIELD, Massachusetts , March 22, 2016 ... and facial recognition with passcodes for superior security ... MESG ), a leading provider of secure digital communications ... pilot their biometric technology and offer enterprise customers, particularly ... provide secure facial recognition and voice authentication within a ...
(Date:3/17/2016)... ABI Research, the leader in transformative ... market will reach more than $30 billion by ... Consumer electronics, particularly smartphones, continue to boost the ... reach two billion shipments by 2021 at a ... Research Analyst at ABI Research. "Surveillance is also ...
(Date:3/15/2016)... , March 15, 2016 Yissum Research ... the technology-transfer company of the Hebrew University, announced today ... remote sensing technology of various human biological indicators. Neteera ... $2.0 million from private investors. ... on the detection of electromagnetic emissions from sweat ducts, ...
Breaking Biology News(10 mins):