. 24/7 Space News .
TECH SPACE
A curious quirk brings organic diode lasers one step closer
by Staff Writers
University Park PA (SPX) Nov 23, 2017


A red laser beam shines on a card bearing a replica of Penn State's academic logo.

Since their invention in 1962, semiconductor diode lasers have revolutionized communications and made possible information storage and retrieval in CDs, DVDs and Blu-ray devices. These diode lasers use inorganic semiconductors grown in elaborate high vacuum systems.

Now, a team of researchers from Penn State and Princeton University have taken a big step toward creating a diode laser from a hybrid organic-inorganic material that can be deposited from solution on a laboratory benchtop.

"It's usually not a big leap to turn a light emitting diode into a laser," said Chris Giebink, assistant professor of electrical engineering, Penn State. "You essentially just add mirrors and drive it harder. Once organic light-emitting diodes were invented 30 years ago, everybody thought that as soon as we had relatively efficient OLEDs, that an organic laser diode would soon follow."

As it turned out, organic diode lasers proved to be really hard to make.

An organic laser diode could have advantages. First, because organic semiconductors are relatively soft and flexible, organic lasers could be incorporated into new form factors not possible for their inorganic counterparts.

While inorganic semiconductor lasers are relatively limited in the wavelengths, or colors, of light they emit, an organic laser can produce any wavelength a chemist cares to synthesize in the lab by tailoring the structure of the organic molecules. This tunability could be very useful in applications ranging from medical diagnostics to environmental sensing.

Nobody has yet succeeded in making an organic laser diode, but the key may well involve related materials - organic/inorganic perovskites - that have gotten a lot of attention in the research community over the last few years. This hybrid material has already been responsible for a meteoric rise in the efficiency of photovoltaics, Giebink said.

Perovskites are fairly common minerals that share a similar cubic crystal structure. Somewhat paradoxically, one of the reasons these hybrid perovskite materials work so well in solar cells is that they are good light emitters.

For that reason, they are also of interest for use in LEDs and lasers. The material Giebink and his colleagues are studying is composed of an inorganic perovskite sublattice with relatively big organic molecules confined in the middle.

"The ultimate goal is to make an electrically driven perovskite laser diode," said Giebink.

"That would be a game changer. It is fairly easy to make the perovskite material lase by optical pumping, that is, by shining another laser on it. However, this has only worked for very short pulses due to a poorly understood phenomenon we call lasing death.

Getting it to go continuously is a key step toward an eventual electrically driven device. What we found in this recent study is a curious quirk. We can avoid lasing death entirely just by lowering the temperature of the material a little bit to induce a partial phase transition."

In a paper published online Nov. 20 in the journal Nature Photonics, Giebink and colleagues report the first "Continuous-wave lasing in an organic-inorganic lead halide perovskite semiconductor."

"When we lowered the temperature below the phase transition, we were surprised to find that the material initially emitted light from the low temperature phase, but then changed over within 100 nanoseconds and began lasing from the high-temperature phase - for over an hour," said Yufei Jia, a graduate student in Giebink's lab and lead author.

"It turned out that as the material heated up, although most of the material remained in the low-temperature phase, small pockets of the high-temperature phase formed, and that was where the lasing was coming from."

In some inorganic lasers there are narrow regions called quantum wells where charge carriers can be trapped as the electrons and holes fall into the wells. The intensity of the lasing depends on how many charge carriers can be packed into the quantum wells.

In the perovskite material, the arrangement of the high-temperature-phase inclusions inside the low temperature bulk seems to mimic these quantum wells and may play a role in enabling the continuous lasing.

"The jury is still out on this explanation," Giebink said. "It may be something more subtle."

Nevertheless, these results do point toward an opportunity to engineer a material that has the built-in qualities of this mixed phase arrangement, but without having to actually cool the material to low temperature.

The current paper points to a couple of ideas for how those materials could be designed. The next big step then is to switch from optical pumping with an external laser to a perovskite laser diode that can be powered directly with electrical current.

"If we can solve the electrical pumping problem, perovskite lasers could turn into a technology with real commercial value," Giebink said.

TECH SPACE
Plasma from lasers can shed light on cosmic rays, solar eruptions
Plainsboro NJ (SPX) Nov 13, 2017
Lasers that generate plasma can provide insight into bursts of subatomic particles that occur in deep space, scientists have found. Such findings could help scientists understand cosmic rays, solar flares and solar eruptions - emissions from the sun that can disrupt cell phone service and knock out power grids on Earth. Physicists have long observed that particles like electrons and atomic ... read more

Related Links
Penn State
Space Technology News - Applications and Research


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TECH SPACE
New motion sensors major step towards cheaper wearable technology

Can a magnetic sail slow down an interstellar probe

SSL Selected to Conduct Power and Propulsion Study for NASA's Deep Space Gateway Concept

MDA Selects AdaCore's GNAT Pro Assurance Development Platform for ISS Software

TECH SPACE
Aerojet Rocketdyne supports ULA Delta II launch of JPSS-1

Old Rivals India, China Nurture New Rivalry in Satellite Launch Business

NASA launches next-generation weather satellite

SpaceX postpones launch of secretive Zuma mission

TECH SPACE
Winds Blow Dust off the Solar Panels Improving Energy Levels

Recurring Martian Streaks: Flowing Sand, Not Water?

From Hannover around the world and to the Mars: LZH delivers laser for ExoMars 2020

NASA Selects Instrument for Future International Mission to Martian Moons

TECH SPACE
China plans for nuclear-powered interplanetary capacity by 2040

China plans first sea based launch by 2018

China's reusable spacecraft to be launched in 2020

Space will see Communist loyalty: Chinese astronaut

TECH SPACE
Space Launch plans UK industry tour

Astronaut meets volcano

European Space Week starts in Estonia

New Chinese sat comms company awaits approval

TECH SPACE
New way to write magnetic info could pave the way for hardware neural networks

Borophene shines alone as 2-D plasmonic material

Metal membranes in construction: From Russia with love

Spin current from heat: New material increases efficiency

TECH SPACE
Lava or Not, Exoplanet 55 Cancri e Likely to have Atmosphere

Images of strange solar system visitor peel away some of the mystery

Familiar-Looking Messenger from Another Solar System

Space dust may transport life between worlds, research suggests

TECH SPACE
Pluto's hydrocarbon haze keeps dwarf planet colder than expected

Jupiter's Stunning Southern Hemisphere

Watching Jupiter's multiple pulsating X-ray Aurora

Help Nickname New Horizons' Next Flyby Target









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.