The Future of Smart Lighting Seems Bright, But Is That Really True?

Smart bulbs are cool. A 2015 survey by Osram Sylvania, a titan in the lighting industry, says 62% of Americans are aware smart bulbs exist, but only 10% have gone out and purchased any. That's a pretty sizeable gap. So why, when there are so many reasons to buy a smart bulb, are only 10 percent of Americans spending their hard earned money on this premier technology of the future? Smart bulbs aren't just about "color", their about interactive experiences. You're watching "The Shape of Water" with your family and the monster is revealed. Then, like magic, your entire living room turns green! Does that really sound appealing? Maybe to some, it does. I, apparently, am not amongst them.

Noisy LEDs annoy

A press release back in September 2017 by the DARC (the amateur radio club of Germany) announced their concern for a significant increase in environmental RF noise causing interference to radio communications, broadcast radio and even DAB reception. They lay the blame firmly at the door of LED lighting and the widespread use of poorly designed and (RF) noisy LED products. Tests carried out by Elektor on these LED lamps (and also LED lighting strips) confirmed their suspicions. The Federal Network Agency now welcomes our initiative to get you to send in any suspect LED lamp so we can carry out tests on them.

This Smart Light Bulb Adds a Splash of Color to Any Space

Bring your indoor space to life with the Illumi Color PAR30 Spot Smart Light Bulb. This RGB LED light bulb can enhance any room, thanks to a wide range of color and brightness settings that are totally customizable from the companion app. Each bulb offers a bright, directional beam with a 900 lumen output (equivalent to a 65-watt incandescent spotlight bulb). The bulbs communicate with your phone via Bluetooth, and are expected to last up to 20 years. They’re also five times more energy efficient than standard incandescent light bulbs, so you’ll be saving energy and money. Now that’s a win-win.

Is 'Blue Light' Really That Bad for Us?

Blue light will get you if you don't watch out. That's the message from the advertisers of blue-blocking glasses, computer monitors, and apps for cell phones and tablets. Their websites warn of eye strain, retina damage, and insomnia from the widespread use of light-emitting diodes (LEDs) in these devices and in light bulbs. "Overexposure to blue light could cause all kinds of problems, including dry eyes to digital eye strain, sleep cycle disruption, and even macular degeneration," Lens Crafters warns. "Blue light gives damage to the inner part of your eye," claims the maker of the AceColor app for iPhones. The Vision Council, a consortium of eyewear manufacturers, lists "blue light filter" as a feature of computer glasses that can "prevent the headaches and light sensitivity that people who spend long hours staring at a monitor often experience."

Nobel Prize Winner Sheds Light on the Future of LEDs

Advances in lighting technology are improving the quality and safety of everything – from cars to computer screens and cell-phones – and some day may make ubiquitous Wi-Fi net works obsolete.That’s the message Nobel laureate Shuji Nakamura, a researcher at the University of California, Santa Barbara, delivered to a packed audience recently at University Crossing.  “Laser diodes are the light of the future,” said Nakamura, who was on campus to deliver this year’s Tripathy Endowed Memorial Lecture and receive an honorary doctorate. More than 100 students, faculty and staff were on hand for the event.

Osram Warns of Lighting Slowdown for Second Time This Year

Osram AG warned investors for a second time this year of a slump in performance at the former Siemens AG lighting division, and said it will begin talks with labor groups to implement cost-saving measures. The shares fell in extended trading after Osram late Tuesday cut its 2018 forecast, blaming a first-half slowdown and a weaker dollar that added to the strain on revenue. The Munich-based company, which gets more than 20 percent of its sales in the U.S., was already dealing with challenges in automotive-headlamp sales, while its beleaguered light-fixtures unit is under review for a possible sale.

To understand LED lighting lifetime, you must consider a bigger picture

Anyone who’s been in the solid-state lighting (SSL) industry for any length of time knows this number: 50,000 hours. When asked about the expected lifetime of an LED, it’s probably the most common answer. It’s also a number that needs a lot of context. 50,000 is such a large number that it’s helpful to translate it into more familiar terms; 50,000 hours is about five years and nine months. Has someone actually lit the LEDs in question continuously for five years and nine months? Maybe. Probably not. Think about it: The LED industry is changing so quickly that by the time someone tested an LED for almost six years, that type of LED would be obsolete.

Larson Electronics LLC Releases 2000W High Intensity LED Light Mast with Hydraulic Assist

Industrial lighting expert, Larson Electronics LLC, has announced the release of a hydraulic light mast that deploys 140,000 lumens of LED light up to thirty feet. This light tower features a removable mast head for storage, with a 360º rotating boom and four 500-watt high output LEDs for high quality, intense illumination, and is ideal for temporary lighting and construction sites where vibration, dust, dirt and other abusive working conditions exist.

The LM-HA-30-9-5S-FM-4X500LTL-LED from Larson Electronics is a telescoping 5 stage light mast with hydraulic assist that allows the quick and safe deployment of four 500-watt light heads with Bridgelux LEDs and other equipment up to 30 feet high and can be collapsed to 9 feet. The tower itself is built with steel square tubing coated with a glossy blue corrosion resistant finish. The 360º telescoping mast is elevated with the press of a button to its upright position. This chain-driven light tower folds over for easy transportation and is powered by a hydraulic ram at stage 1 of the unit for simple and fast deployment of electrical equipment. This lighting tower system also features a mounting plate provides a stable platform for light fixtures and equipment, and a proprietary mast guidance system to help this unit withstand winds up to 125 mph.

Morgan Stanley Switches 600 Branches To Energy-Efficient Lighting

Morgan Stanley is collaborating with GE’s energy-focused startup Current to upgrade lighting at more than 600 retail branches. The companies say they expect the program to reduce lighting-related energy consumption by as much as 50% in some branches. Current plans to work with Morgan Stanley on evaluating energy savings opportunities across the branch locations and providing a turnkey LED lighting and digital controls solution. Morgan Stanley says that the program, being done in partnership with Hines real estate management, should provide the company with enterprise-level visibility.

LEDs Set To Ignite The Big Board

Grand View Research’s recent report says the global LED lighting market size is expected to reach $108.99 billion by 2025 and will register a CAGR of 14.4% during the forecast period. Continuous development of energy-saving capabilities, introduction of Standard Deviation Color Matching (SDCM) control, and longer lifespan compared to CFL lamps have accelerated demand for LED lamps at a global level. Introduction of smart/connected lighting and its multiple uses in residential, commercial, and industrial sectors has also spurred market growth. Other highlights: The indoor LED lighting segment held the largest share in 2016 and is anticipated to register a comparatively lower growth rate from 2017 to 2025. OLED emerged as the largest product segment in 2016 and is estimated to generate revenue worth USD 58.0 billion by 2025

Campaign Continues For Lighting Emerson Soccer Fields

Terry Wolf, superintendent of Buildings and Grounds for the Park Ridge Park District, announced plans to make a presentation later this month to the Park Ridge-Niles School Dist. 64 board to seek permission to install LED lights on Emerson Middle School’s playing fields. This would help accommodate more evening games for the Park Ridge Soccer Club. Emerson is in Niles, as are most of the neighbors north of Oakton who are closest to the fields. This means clearing permissions from the school district and the village of Niles, and addressing neighbors’ concerns.

What to know before you buy vintage-style LED light bulbs

You'll find all sorts of light bulbs in your local lighting aisle, but more and more, we're seeing bulbs that fall under labels like vintage-style. The pitch for lights like these is pretty simple: new-age LED efficiency paired with old-school incandescent looks, right down to the fake LED "filaments" inside of the bulb. Vintage-style bulbs started out as a nostalgic novelty for folks who weren't ready to say goodbye to the incandescent bulbs getting phased out by rising energy standards, but with big names like GE, Philips, Feit and others jumping in with the trend, they've become a legitimate category of their own. These days, most lighting aisles afford them their own, dedicated section.

Singapore to test facial recognition on lamp posts

In the not too distant future, surveillance cameras sitting atop more than 100,000 lamp posts in Singapore could help authorities recognise faces in crowds across the city state. The plan to install the cameras, which will be linked to facial recognition software, is raising privacy fears among security experts and rights groups. The government said the system would allow it to “perform crowd analytics” and support anti-terror operations.

Mc Lighting Takes the Pain out of Blinking

If you want to blink a ton of WS2812-alike LED pixels over WiFi, the hardware side of things is easy enough: an LED strip, and ESP8266 unit, and a beefy enough power supply to feed them. But the software side — that’s where it can be a bit of a pain. Enter Mc Lighting. It makes the software side of things idiot-proof. Flash the firmware onto the ESP8266, and you’ve got your choice of REST, WebSockets, or MQTT to get the data in. This means that it’ll work with Homekit, NodeRed, or an ESP-hosted web interface that you can pull up from any smartphone.

LED streetlights are coming to Philadelphia. Will they mess with our sleep?

Walk down a Philadelphia street at night and most likely, you will find the city lit in a warm yellow glow. The familiar cast comes from high-pressure sodium lights — the conventional breed of streetlamp common in the city. But soon, those yellow nights will be a memory. Instead, Philadelphia will take on a whitish cast as the city’s Streets Department moves forward with a long-anticipated plan to replace its old bulbs with more energy efficient LEDs. But as the city moves forward with the lighting makeover, experts are urging officials to consider public health and environmental questions raised by a 2016 study by the American Medical Association of the impact of LED lights.

SolarMax LED Outdoor Lighting Systems Make Parks Smarter

Two forward looking cities in LA County have cast new light - provided by SolarMax LED - on the fiscal challenge of replacing old, inefficient outdoor lighting systems. City councils in El Monte and Carson have approved installation of new wireless LED systems, part of a region-wide Smart & Safe Parks initiative that enhances public safety and energy conservation, while reducing maintenance costs.

An innovative zero-down financing model from SolarMax LED enabled each city to minimize upfront investment and recover costs through improved operating efficiencies. Lead contractor ACS Group forecasted the estimated savings on the Mountain View project alone at more than $241,000 over the first five years.

In addition to the SolarMax LED component, the Smart & Safe Parks initiative includes a separate video surveillance camera system as well as an expanded community Wi-Fi network that will deliver broadband access to underserved residential neighborhoods and school districts. CIOPRO, a technology integration specialist, formed the consortium of partner companies involved in system build out.

The fully integrated system runs over a wireless network powered by Cisco Systems. Functionality enables facilities managers to remotely monitor and control variables such as LED lighting consumption, brightness, seasonality, and outages. City personnel can also use the software to position video surveillance cameras for optimal security.

Installing smart lights in a rented home

App-controlled lighting can be the best first step to making your home smarter. These systems are easy to install and set up, can be easily moved to a different room or a new property, and have a certain wow-factor that devices like smart thermostats lack. Although you may only have heard of smart lights from Philips and Ikea, the market is already surprisingly large. All systems offer a very similar promise — millions of colors and temperatures of light, adjustable to however you like — but there are differences to be aware of before you make your first purchase.

Microsoft Patents New Surface Pen With Built-in LEDs

Recently a new patent for the Surface Pen was published which points at the stylus getting some cool new features. The patent which was filed back in February 2017 shows the pen with built-in LEDs. The LEDs can be positioned at the upper part of the pen, near the tip, or in the middle. For the one positioned near the tip, it can be configured to light up in a color that currently matches the one in use. This is helpful for creatives as they don’t have to confirm the color in use by looking at the color palette.

HEB Recalls Halogen Light Bulbs That Could Shatter

HEB stores are recalling halogen light bulbs that could shatter while in use and cause cuts or fires.

There have been 14 reports of light bulbs shattering while in a lamp or light fixture. One consumer had a cut on his hand and another had a burn to his hand and cuts on his foot. According to the Consumer Product Safety Commission, the recall involves GTC halogen light bulbs sold in packages of two or four bulbs. The bulbs were 25 watt, 40 watt, 60 watt, 75 watt or 100 watt bulbs in either clear or soft white colors

Purple light bulbs are sweeping Springfield for Autism awareness

Purple bulbs are shining a light on autism this month across Springfield. "Autism is a neurological disability,” said Amanda Brott, the Chief Operating Officer for Springfield’s Hope Program. She said autism impairs someone's communication and interaction skills. Now, Brott is trying to build a greater understanding. TAP is giving out free purple bulbs throughout the Autism Awareness Month, to homes and businesses like Orange theory fitness.

Osram aims at automotive with high-power IR leds

For automotive applications, Osram has introduced six high-power infra-red leds that can be pulsed at up to 5A (up from 3A in earlier versions). Part of the Oslon Black family, there are 850nm versions intended for exterior applications such as night vision, pedestrian protection, pre-field recognition and lane detection, as well as 940nm versions for interior applications such as driver monitoring, seat occupancy detection and gesture recognition.

Italian designer turns to Toshiba high-CRI leds for classic re-vamp

Lumina Italia, founded by designer Tommaso Cimini in 1975, has been making its Daphine lamp ever since.This year it has been updated to use leds to form the ‘Daphine Tri-R’, using Toshiba’s Tri-R high-colour-rendering leds  which have a violet die and phosphors at multiple wavelengths – scoring >Ra97 for CRI and Qa96 for CQS.The lamp consumes 10.4W and produces 828 lm at a warm 3,048K. It comes in black, white or bronze panted finish, or nickel plated.

100,000 Free Light Bulbs: San Fran Begins History's Largest LED Giveaway

San Francisco has begun handing out 100,000 free LED light bulbs in what it calls the biggest LED bulb giveway in history. Starting Wednesday, the city’s Department of Environment began giving out the light bulbs via three distribution channels. San Francisco purchased the light bulbs by utilizing a 280,000 award from Pacific Gas & Electric Co.

FBH To Present Latest UV LED Developments

Ferdinand-Braun-Institut (FBH) and its spin-off UVphotonics NT will be presenting their latest UV LED developments at the International Conference on UV LED Technologies & Applications 2018 (ICULTA-2018 ) from April 22 to 25 in Berlin. Increased efficiency and output powers plus small size make UV LEDs increasingly attractive for a constantly growing number of applications including disinfecting water, air and surfaces as well as for curing of synthetic materials. UV LEDs can be quickly switched and dimmed, and heat losses are efficiently dissipated via heat sinks. Unlike mercury vapour lamps, UV LEDs consist of non-toxic substances, and their wavelengths can be flexibly adjusted over a wide spectral range.

Councillors asked to consider amber LED lighting

Dunedin city councillors have been given a demonstration of the difference colour could have on LED lighting. Dunedin Dark Skies Group member Michael Broughton asked the councillors, during his submission on the council's 10-year plan yesterday, to consider delaying introduction of the planned LED street lighting programme in the city. About $12million has been set aside in the plan to upgrade the city's street lights to LED lighting, which the council plans to start installing later this year.

Incandescent light bulbs outnumber LEDs across BC

Incandescent light bulbs still rule in BC, despite energy performance standards brought in by the federal government a few years ago that have led many retailers to phase them out. Susie Rieder with BC Hydro explains more than three-quarters of people across the province say they have at least one incandescent bulb in their home. “In those homes that have at least one incandescent, the average number is about 17, so these remain the most widely used type of bulb in BC.” Rieder adds LED bulbs use much less energy that incandescent ones.

How Financially Strong Is SemiLEDs Corporation?

SemiLEDs Corporation (NASDAQ:LEDS) is a small-cap stock with a market capitalization of US$11.66M. While investors primarily focus on the growth potential and competitive landscape of the small-cap companies, they end up ignoring a key aspect, which could be the biggest threat to its existence: its financial health. Why is it important? Companies operating in the Semiconductor industry, especially ones that are currently loss-making, are more likely to be higher risk. So, understanding the company’s financial health becomes essential. Here are few basic financial health checks you should consider before taking the plunge.

Switching to LED lightbulbs saves at least $100 a year: EECA

A typical New Zealand household could save between $100 and $150 a year on its power bill by switching to LED lightbulbs - but half of us still haven't bothered. A new survey commissioned by the Energy Efficiency and Conservation Authority (EECA) showed only half the 500 people it questioned had installed any LED bulbs in their homes. But the rate of take-up is increasing. Three years ago, just 18 per cent had made the switch. An LED lightbulb produces "light-emitting diodes". The bulbs use up to 85 per cent less power to provide the same amount of light as an incandescent bulb. Each LED bulb is meant to last at least 15,000 hours.

East Campus University of (Missouri) to get brighter street lights

The city is ready to fulfill a longtime wish of many East Campus neighborhood property owners and University of Missouri students — new, brighter streetlights. Columbia Water and Light will upgrade 36 existing mercury vapor street lights to LED bulbs, measure light levels at representative locations before and after the lighting upgrade and report back to the Columbia City Council. The lights are being upgraded with brighter bulbs instead of installing more lights after the Environment and Energy Commission recommended against more lights because the neighborhood already has more streetlights than many residential areas of the city.

Indian boy’s body can light up LED light bulbs

A 9-year-old boy from Kerala, in India, has become a social media sensation after videos of him lighting rechargeable LED light bulbs just by touching their electrical contacts with any part of his body went viral online. Abu Thahir, who hails from Muhamma near Alappuzha, Kerala, discovered his unusual power only recently while returning home with his father after buying a rechargeable LED light bulb. His father, Nizar, who happens to be an electrician, told reporters that when he passed the light-bulb to his son, it just lit up in his hand.

Lighting Up a Product Photoshoot Using LEDs

Nordic Automation Systems Introduces LoRaWAN Controller for LEDs

Nordic Automation Systems (NAS) upped their Smart City game, announcing a Zhaga Book 18 compliant luminaire controller. Zhaga is a global lighting industry organization working to standardize components of LED luminaires, including LED light engines, LED modules, LED arrays, holders, electronic control gear (LED drivers) and connectivity fit systems. Book 18 marks Zhaga’s first contribution to the rapidly-emerging world of smart lighting.

Piano playing with LEDs is like Guitar Hero in expert mode

Fluotec to showcase new pro LED lighting lines at NAB Show

Fluotec, a design and manufacturing firm of lighting products and services for the cinema, television, video, photography and theatrical industries will be showcasing its new professional LED lighting lines of fixtures and light control accessories. Last year’s award winning 338W 2K incandescent equivalent Vegalux 300 is a motorized zoom DMX tunable neutral white light LED fresnel that adds now two  new models in dedicated versions of Tungsten 3200K and Daylight 5600K color temperatures.

Multi-Coloured LEDs Make For A Beautiful Colour Clock

Clocks are a recurring feature among the projects we feature here on Hackaday, with several common themes emerging among them. We see traditional clocks with hands, digital clocks with all forms of display including the ubiquitous Nixie tube, and plenty of LED ring clocks. Matt Evans build is one of the final category, a particularly nice LED ring clock using wire-ended multi-colour LEDs. Other clocks produce an effect that looks good from across the room, but this one is also a work of beauty when examined in close-up.

Larson Electronics LLC Releases Explosion Proof Light with 3rd Generation LEDs

Larson Electronics LLC has released a third-generation explosion proof LED paint spray booth light fixture that provides operators in hazardous environments powerful, energy efficient illumination. This four-foot two-lamp fixture is rated for Class I Division 1 &2 and Class II Division 1 & 2 areas, and holds paint spray booth, ATEX and IECEx certifications, making it ideal for paint booths, oil rigs, offshore applications, petrochemical, manufacturing, chemical storage and more.

The EPL-48-2L-LED-G3 explosion proof LED fixture provides 2,250 lumens of high quality light drawing just 36 watts. This two-lamp explosion proof LED linear fixture is lighter in weight, has a slimmer profile, and produces more light than traditional explosion proof fluorescent fixtures. The four-foot-long LED tube design bulbs included with this unit are rated at 50,000 hours of service life, which is over twice as long as standard T8 bulbs. This LED produces a 150º degree beam spread and has a standard 5600K cool white color temperature to produce colors and details more accurately than traditional luminaries. The LEDS in this unit are the newest evolution in LED technology, giving operators the highest efficiency and lowest power consumption on the market.

Downtown would benefit from decorative lighting

Street lighting has divided the Litchfield City Council in a pending decision over cost-efficient versus decorative fixtures for the downtown area. In a city that has consistently supported efforts to complement the appearance of its historic district, it should be a no-brainer. Decorative lighting is the way to go. Although cobra lighting is significantly less expensive than the more-decorative five-globe or acorn-shaped fixtures, the snake-head lookalikes will undoubtedly detract from the appearance of a new Sibley Avenue streetscape when the U.S. Highway 12 reconstruction project is completed in 2020.

Photo: Joe Mabel (cc)

Snag a levitating light bulb for all of your home decor and wizardry needs

Larson Electronics Releases LED Tractor Lighting Package for McCormick International MTX125

Larson Electronics, industrial grade lighting leader, released an LED tractor light package, complete with four LED spot lights, six LED flood lights, and two rectangular LED grill lights. This tractor light kit mounts in existing lamp holders for halogen lamps on McCormick International MTX125 tractors, making it an ideal upgrade solution with high output and increased energy-efficiency.

The LLP-MCC-TR-MTX-125-V2 LED tractor light package is designed for installation and use on McCormick International MTX125 tractors and comes with a total of twelve LED lights. These LEDs include: Ten Larson Electronics’ LEDEQ-3X3-CPR LED work lights, four of which come in a spot beam configuration for rear fender and top front cab lighting, six LEDs in a flood beam configuration for use as rear back cab, mid cab and top front cab illumination, and two Larson Electronics’ IL-LED-DLR-5X2 rectangular LEDs for use as grill lights.

HEB Recalls Halogen Light Bulbs That Could Shatter

HEB stores are recalling halogen light bulbs that could shatter while in use and cause cuts or fires.

There have been 14 reports of light bulbs shattering while in a lamp or light fixture. One consumer had a cut on his hand and another had a burn to his hand and cuts on his foot. According to the Consumer Product Safety Commission, the recall involves GTC halogen light bulbs sold in packages of two or four bulbs. The bulbs were 25 watt, 40 watt, 60 watt, 75 watt or 100 watt bulbs in either clear or soft white colors. The tops of the bulbs read "GTC" along with the wattage and lumens values.

London’s Madame Tussauds Goes LED, Expecting to Cut Lighting Costs by 70%

Madame Tussauds Spirit of London ride has chosen to use LED lighting in an overhaul of it’s equipment. With the ride reaching its 25th anniversary, the on-site AV team were eager to upgrade the attraction’s lighting to more energy efficient, eco-friendly LED fixtures, as part of their overall environmental policy. A.C. Special Projects, a specialist lighting and audio visual installation firm, managed the specification and supply of over 250 various ProLights LED fixtures, including warm and full color-mixing luminaires providing discreetly installed full set, scenic, key and effects lighting.

Birdnow Dealership upgrades to new LED lighting system

As a way to increase energy efficiency and light brightness, Birdnow Dealership in Oelwein has upgraded to an LED lighting system. After putting out several bids, Birdnow Dealership went with the LED Lighting Crew from Cedar Rapids to install the new LED lighting system. Jeremy Birdnow said the LED lighting system will consume less energy and be better for the environment. The main reason we looked into doing this was obviously the cost effectiveness of LEDs over time compared to what we had,” Birdnow said. “It was more energy efficient. Going green is obviously very important, not only for vehicles, but for our buildings.”

Atomically thin light emitting device opens the possibility for ‘invisible’ displays

UC Berkeley engineers have built a bright-light emitting device that is millimeters wide and fully transparent when turned off. The light emitting material in this device is a monolayer semiconductor, which is just three atoms thick.

The device opens the door to invisible displays on walls and windows – displays that would be bright when turned on but see-through when turned off — or in futuristic applications such as light-emitting tattoos, according to the researchers.

“The materials are so thin and flexible that the device can be made transparent and can conform to curved surfaces,” said Der-Hsien Lien, a postdoctoral fellow at UC Berkeley and a co-first author along with Matin Amani and Sujay Desai, both doctoral students in the Department of Electrical Engineering and Computer Sciences at Berkeley.

Their study was published March 26 in the journal Nature Communications. The work was funded by the National Science Foundation and the Department of Energy.

The device was developed in the laboratory of Ali Javey, professor of Electrical Engineering and Computer Sciences at Berkeley. In 2015, Javey’s lab published research in the journal Science showing that monolayer semiconductors are capable of emitting bright light, but stopped short of building a light-emitting device. The new work in Nature Communications overcame fundamental barriers in utilizing LED technology on monolayer semiconductors, allowing for such devices to be scaled from sizes smaller than the width of a human hair up to several millimeters. That means that researchers can keep the thickness small, but make the lateral dimensions
(width and length) large, so that the light intensity can be high.

Commercial LEDs consist of a semiconductor material that is electrically injected with positive and negative charges, which produce light when they meet. Typically, two contact points are used in a semiconductor-based light emitting device; one for injecting negatively charged particles and one injecting positively charged particles. Making contacts that can efficiently inject these charges is a fundamental challenge for LEDs, and it is particularly challenging for monolayer semiconductors since there is so little material to work with.

The Berkeley research team engineered a way to circumvent this challenge by designing a new device that only requires one contact on the semiconductor. By laying the semiconductor monolayer on an insulator and placing electrodes on the monolayer and underneath the insulator, the researchers could apply an AC signal across the insulator. During the moment when the AC signal switches its polarity from positive to negative (and vice versa), both positive and negative charges are present at the same time in the semiconductor, creating light.
The researchers showed that this mechanism works in four different monolayer materials, all of which emit different colors of light.

This device is a proof-of-concept, and much research still remains, primarily to improve efficiency. Measuring this device’s efficiency is not straightforward, but the researchers think it’s about 1 percent efficient. Commercial LEDs have efficiencies of around 25 to 30 percent.

The concept may be applicable to other devices and other kinds of materials, the device could one day have applications in a number of fields where having invisible displays are warranted. That could be an atomically thin display that’s imprinted on a wall or even on human skin.