Light / en Bright ideas: researchers, entrepreneurs, industry leaders at U of T conference exploring future of light /news/bright-ideas-researchers-entrepreneurs-industry-leaders-u-t-conference-exploring-future-light <span class="field field--name-title field--type-string field--label-hidden">Bright ideas: researchers, entrepreneurs, industry leaders at U of T conference exploring future of light</span> <div class="field field--name-field-featured-picture field--type-image field--label-hidden field__item"> <img loading="eager" srcset="/sites/default/files/styles/news_banner_370/public/Venkat%20Venkataramanan%20%28for%20web%20lead%29.jpg?h=afdc3185&amp;itok=dVmYEHG2 370w, /sites/default/files/styles/news_banner_740/public/Venkat%20Venkataramanan%20%28for%20web%20lead%29.jpg?h=afdc3185&amp;itok=A8_k5BFy 740w, /sites/default/files/styles/news_banner_1110/public/Venkat%20Venkataramanan%20%28for%20web%20lead%29.jpg?h=afdc3185&amp;itok=8zMcxpju 1110w" sizes="(min-width:1200px) 1110px, (max-width: 1199px) 80vw, (max-width: 767px) 90vw, (max-width: 575px) 95vw" width="740" height="494" src="/sites/default/files/styles/news_banner_370/public/Venkat%20Venkataramanan%20%28for%20web%20lead%29.jpg?h=afdc3185&amp;itok=dVmYEHG2" alt="Venkat Venkataramanan picture"> </div> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>Christopher.Sorensen</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2017-05-01T14:58:03-04:00" title="Monday, May 1, 2017 - 14:58" class="datetime">Mon, 05/01/2017 - 14:58</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">Venkat Venkataramanan, the director of scientific operations at U of T's Impact Centre, adjusts a light demo in his lab (photo by Chris Sorensen) </div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/chris-sorensen" hreflang="en">Chris Sorensen</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Chris Sorensen</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/startup" hreflang="en">Startup</a></div> <div class="field__item"><a href="/news/tags/entrepreneurship" hreflang="en">Entrepreneurship</a></div> <div class="field__item"><a href="/news/tags/light" hreflang="en">Light</a></div> <div class="field__item"><a href="/news/tags/impact-centre" hreflang="en">Impact Centre</a></div> <div class="field__item"><a href="/news/tags/u-t-mississauga" hreflang="en">U of T Mississauga</a></div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Most associate insomnia with the dark. But <strong>Amol Rao</strong> says we should pay more attention to our lights.</p> <p>The U of T student, who will soon be graduating with a master's degree&nbsp;in industrial engineering, cites a growing body of research that shows nighttime exposure to blue wavelength light – the type that illuminates our smartphones, tablets and laptops –&nbsp;messes with the body’s internal clock, tricking it into believing it’s the middle of the day.&nbsp;</p> <p>“Light is like coffee,” explains Rao. “If you had a cup at 10 p.m., most people would expect it to have an effect on their sleep.”&nbsp;</p> <p>The solution for those unwilling to unplug? Rao says lighting manufacturers will eventually shift the wavelengths of smart bulbs depending on the time of day. In the meantime, he suggests donning a pair of orange-tinted, blue-blocking sunglasses before bed – like the ones sold by&nbsp;<a href="https://blueblockglasses.com/">Somnitude</a>, a startup firm he founded with partner <strong>Daniel Giavedoni</strong>.</p> <p>Somnitude will have its products on display this week at a U of T Mississauga conference held by&nbsp;<a href="http://www.sslnet.ca/">U of T’s Smart Sustainable Lighting Network (SSLN)</a>,&nbsp;the country’s largest and most active cluster of lighting-focused researchers and industry participants. The group, part of the university’s&nbsp;<a href="http://www.impactcentre.ca/">Impact Centre</a>&nbsp;business accelerator, works with lighting manufacturers and other partners to promote the development and adoption of sustainable lighting technologies in Canada.&nbsp;</p> <p><img alt="Amol Rao picture" class="media-image attr__typeof__foaf:Image img__fid__4444 img__view_mode__media_original attr__format__media_original" src="/sites/default/files/Amol%20Rao%20%28for%20web%20embed%29.jpg" style="width: 750px; height: 500px;" typeof="foaf:Image"><br> <em>Amol Rao shows off Somnitude's blue-blocking glasses at U of T's Impact Centre accelerator&nbsp;(photo by Chris Sorensen)</em></p> <p>The focus of this year's&nbsp;<a href="http://www.sslnet.ca/events/conf2017/">Beyond Lighting</a>&nbsp;event, which runs from May 2-4,&nbsp;is to use&nbsp;LEDs to accomplish more than mere illumination.</p> <h3><a href="http://entrepreneurs.utoronto.ca/">Learn more about entrepreneurship and startups at U of T</a></h3> <p><strong>Venkat Venkataramanan</strong>, who founded&nbsp;SSLN&nbsp;and is Impact Centre's director of scientific operations, says the shift reflects the fact that mass market adoption of sustainable, energy efficient LED lights is now well underway, leaving researchers and industry with&nbsp;time to explore novel applications.&nbsp;</p> <p>The relationship between light and health – Somnitude's focus&nbsp;of interest&nbsp;– looks particularly promising.</p> <p>Boeing, for example, already uses shifting colours of&nbsp;LED light in its 787 aircraft cabins to try and blunt the effects of jet lag. Referring to the blinding fluorescent lights that now hang over many people's heads, Venkataramanan likens the current era of lighting to eating fast-food. We're now moving toward a more gourmet experience, he says.</p> <p>The conference's&nbsp;keynote address is being delivered by University&nbsp;of Montreal Professor Marie Dumont, who has spent the past 25 years studying the effects of different types of light on biological rhythms, sleep disorders and cognitive function. Other presenters&nbsp;will talk about how LED lights can be used as tools to boost the yield of greenhouses or even act as&nbsp;routers to connect smart devices in people homes.&nbsp;</p> <p>Some&nbsp;technologies are already making their way to the marketplace.</p> <p><a href="/news/indoor-farming-takes-root-u-t-mississauga"><strong>Conner Tidd</strong> is co-founder of another U of T startup Just Vertical.</a> The firm is adapting the LED-lit vertical growing technology of a partner company, called ZipGrow, so people can grow fresh fruits and vegetables in their houses and condos.</p> <p>“We’ve grown over 30 different kinds of plants so far,” Tidd says, listing everything from kale to strawberries. The company is offering to rent equipment and seedlings to budding urban gardeners in Greater Toronto for as little as $100 a month.</p> <p>Just Vertical’s focus on rentals hints at another shift happening in the lighting industry: the business model. Where once lighting manufacturers could count on bulbs burning out and needing to be replaced, the long, multi-decade lifespan of many LED fixtures means many manufacturers need to develop new revenue streams to, in effect, keep the lights on.&nbsp;</p> <p>“Lighting will be a service,” predicts Venkataramanan, who founded his own lighting startup several years ago to help manufacturers test and measure their LEDs. “It will be an enabler for other things.”</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> Mon, 01 May 2017 18:58:03 +0000 Christopher.Sorensen 107057 at Polanyi Prize goes to U of T researcher for his work on more efficient solar materials /news/polanyi-prize-goes-u-t-researcher-his-work-more-efficient-solar-materials <span class="field field--name-title field--type-string field--label-hidden">Polanyi Prize goes to U of T researcher for his work on more efficient solar materials </span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>sgupta</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2015-11-17T07:57:54-05:00" title="Tuesday, November 17, 2015 - 07:57" class="datetime">Tue, 11/17/2015 - 07:57</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">(photo by Marit Mitchell)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/marit-mitchell" hreflang="en">Marit Mitchell</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Marit Mitchell</div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/more-news" hreflang="en">More News</a></div> <div class="field__item"><a href="/news/tags/prizes" hreflang="en">Prizes</a></div> <div class="field__item"><a href="/news/tags/physics" hreflang="en">Physics</a></div> <div class="field__item"><a href="/news/tags/lighting" hreflang="en">Lighting</a></div> <div class="field__item"><a href="/news/tags/light" hreflang="en">Light</a></div> <div class="field__item"><a href="/news/tags/led" hreflang="en">LED</a></div> <div class="field__item"><a href="/news/tags/honours" hreflang="en">Honours</a></div> <div class="field__item"><a href="/news/tags/engineering" hreflang="en">Engineering</a></div> <div class="field__item"><a href="/news/tags/awards" hreflang="en">Awards</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">Engineering postdoc one of five recognized as outstanding Ontario researchers in early states of their careers</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p><strong>Riccardo Comin</strong>, a postdoctoral fellow in <a href="http://www.ece.utoronto.ca/">The Edward S. Rogers Sr. Department of Electrical &amp; Computer Engineering</a>, has won the <a href="http://cou.on.ca/about/awards/john-charles-polanyi/">2015 John Charles Polanyi Prize for Physics</a> for his research into a rapidly emerging new class of materials, called perovskites, for more efficient solar cells and lighting.</p> <p>The Polanyi Prizes are given annually to outstanding researchers in the early stages of their careers. The prizes, worth $20,000 each, are awarded in five areas: physics, chemistry, physiology or medicine, literature and economic science. Comin is the only recipient from the Ƶ this year. (<a href="http://news.utoronto.ca/tags/polanyi-prize">Read about some of U of T's previous&nbsp;Polanyi Prize winners</a>.)</p> <p>“By scientific upbringing, I’m a solid state physicist,” said Comin. “I take new compounds, films or crystals, crafted by chemists, and I analyze them to figure out what’s special about those materials.”</p> <p>Comin’s work, under the direction of Professor <strong>Ted Sargent</strong>, is to investigate the mysterious properties of a very special family of hybrid organic-inorganic materials called perovskites. Perovskites show great promise for a range of applications, from more efficient LED technologies to high-efficiency flexible and lightweight solar cells.</p> <p>Read more about Comin’s recent work, published in the journals<em> Science</em> and <em>Nature</em>:</p> <ul> <li><a href="http://news.utoronto.ca/new-technique-could-lead-cheaper-more-efficient-solar-power-and-leds">Crystal light: New family of light-converting materials points to cheaper, more efficient solar power and LEDs</a></li> <li><a href="http://news.utoronto.ca/fiat-lux-what-do-you-get-when-you-combine-perovskite-and-colloidal-dots">Engineered hybrid crystal opens new frontiers for high-efficiency lighting</a></li> </ul> <p>“My work in the Sargent Group has been to explore various key characteristics of perovskites, including their chemical composition, crystalline structure, and electronic structure,” said Comin. “Thanks to the Polanyi Prize, I plan to expand my work into using x-ray methods to look at the collective phenomena involving the reorientation of the organic molecules embedded in the inorganic crystalline structure of these hybrid materials.”</p> <p>Comin earned his bachelor’s and master’s degrees at the Universita degli Studi di Trieste in Italy, both in physics. He completed his PhD at the University of British Columbia under the supervision of Andrea Damascelli, where he worked on characterizing quantum materials. When he joined the Sargent Group for his postdoctoral fellowship, he was ready to take a more applied approach to his research.</p> <p>“I’d done a lot of fundamental materials science, and I was thinking, ‘What are the strategies and processes involved in harnessing and functionalizing the material properties that are key for devices that realize solar, imaging or lighting applications?’” he said “Here, we’re trying not just to develop high-quality materials, but also to combine them into device architectures that use the best properties of these materials. Ultimately, the metric for the quality of the work is the efficiency and performance of our devices.”</p> <p>The John Charles Polanyi prize was created in honour of the achievement of <strong>John Charles Polanyi,</strong> recipient of the 1986 Nobel Prize in Chemistry and a professor in the Ƶ’s department of chemistry.</p> <p>“My congratulations to Riccardo, who is doing exceptional research,” said Professor Sargent, vice-dean, research for the Faculty of Applied Science &amp; Engineering, and Comin’s supervisor.</p> <p>“It’s particularly wonderful to see him honoured with this award, named after one of the greatest investigators in the Ƶ’s long history.”</p> <p><a href="http://cou.on.ca/articles/polanyi-prizes-celebrate-five-ontario-researchers-for-their-outstanding-achievements/">Learn more about the other 2015 John Charles Polanyi winners</a></p> <p><em>Marit Mitchell is a writer with the Faculty of Applied Science &amp; Engineering at the Ƶ</em></p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> <div class="field field--name-field-picpath field--type-string field--label-above"> <div class="field__label">picpath</div> <div class="field__item">sites/default/files/2015-11-17-Comin_cropped.jpg</div> </div> Tue, 17 Nov 2015 12:57:54 +0000 sgupta 7453 at Solar-powered lamp from U of T to transform lives in Philippines /news/solar-powered-lamp-u-t-transform-lives-philippines <span class="field field--name-title field--type-string field--label-hidden">Solar-powered lamp from U of T to transform lives in Philippines</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>sgupta</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2015-11-05T01:52:50-05:00" title="Thursday, November 5, 2015 - 01:52" class="datetime">Thu, 11/05/2015 - 01:52</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item">(all photos by Neda Ghazi)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/terry-lavender" hreflang="en">Terry Lavender</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Terry Lavender</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/global-lens" hreflang="en">Global Lens</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/features" hreflang="en">Features</a></div> <div class="field__item"><a href="/news/tags/social-entrepreneurship" hreflang="en">Social Entrepreneurship</a></div> <div class="field__item"><a href="/news/tags/lighting" hreflang="en">Lighting</a></div> <div class="field__item"><a href="/news/tags/light" hreflang="en">Light</a></div> <div class="field__item"><a href="/news/tags/international" hreflang="en">International</a></div> <div class="field__item"><a href="/news/tags/impact-centre" hreflang="en">Impact Centre</a></div> <div class="field__item"><a href="/news/tags/entrepreneurship" hreflang="en">Entrepreneurship</a></div> <div class="field__item"><a href="/news/tags/engineering" hreflang="en">Engineering</a></div> <div class="field__item"><a href="/news/tags/bbcie" hreflang="en">BBCIE</a></div> <div class="field__item"><a href="/news/tags/global" hreflang="en">Global</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">Cynthia Goh: “A poor fisherman or farmer who’s been working all day does not want to have to keep pumping a flashlight in order to light his house.”</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Thanks to U of T’s <a href="http://www.impactcentre.ca/about-us">Impact Centre</a>, people in rural parts of the Philippines may soon get access to something that the western world takes for granted: being able to walk into a dark room, flick a switch and get instant light.</p> <p>Professor&nbsp;<strong>Cynthia Goh</strong>, the Centre’s director, said rural areas of the Philippines, along with other regions of the global south, rarely have access to electricity.</p> <p>The Philippines are close to the equator, so “it goes from very bright to very dark within a few minutes,” Goh said.&nbsp;“The sun goes down at 6 p.m. sharp and rises at 6 a.m. every day, which means for 12 whole hours, inhabitants are not able to study, do housework, or be productive.”</p> <p>To celebrate the <a href="http://www.light2015.org/Home.html">2015 International Year of Light</a>, the Impact Centre – part of <a href="http://entrepreneurs.utoronto.ca/">U of T's Banting &amp; Best Centre for Innovation &amp; Entrepreneurship</a>&nbsp;–&nbsp;set itself a goal to create a reliable, low-cost light that provides at least four hours of light a day.</p> <p>“We want it to be bright enough and a good enough quality so that a child can read and a mother can cook,” Goh said.</p> <p><img alt="photo of person turning on a light by pulling a string" src="/sites/default/files/2015-11-03-light-impact-turn-on.jpg" style="width: 275px; height: 413px; margin: 10px; float: right;">The light also had to be easy to use, she said. Many lighting solutions designed for developing countries require winding up or pumping, or only provide inadequate, short-term light, she said.</p> <p>“A poor fisherman or farmer who’s been working all day does not want to have to keep pumping a flashlight in order to light his house. Just because people are poor, doesn’t mean that they should be subject to inconveniences.”&nbsp;</p> <p>The Impact Centre's lighting solution is a&nbsp;great example of the kind of social entrepreneurship that flourishes at U of T,&nbsp;said <strong>Karen Sievewright</strong>, director of U of T's <a href="http://entrepreneurs.utoronto.ca/">Banting &amp; Best Centre for Innovation &amp; Entrepreneurship</a>.</p> <p>“The breadth and depth of research coupled with a wide range of support at the university allows our entrepreneurs to bring better, smarter and more sustainable lighting to the world.”&nbsp;</p> <h2><a href="http://news.utoronto.ca/social-entrepreneurship-explained">Read more about social entrepreneurship</a></h2> <h2><a href="http://news.utoronto.ca/tags/lighting">Read more about lighting innovations from U of T</a></h2> <p>Goh and her Impact Centre colleagues unveiled their solution at an <a href="http://www.impactcentre.ca/light2015">International Year of Light symposium on Oct.&nbsp;29 at U of T</a>: a ceiling-mounted solar-powered lamp that incorporates 16 LEDs and provides 500 lumens of light for four hours, or dimmer light for a longer period of time.</p> <p>The lamp, which can be turned on just by touching a cord, was developed over the summer by a team of Impact Centre engineers. It is expected to cost about $24, which can be paid by instalments. The lithium ion battery will last about a year and will cost about $12.</p> <p>The actual lamps will be assembled, distributed and sold by small businesses in the Philippines. Four lamps will be installed as a pilot test in December 2015.</p> <p>“We’ll get feedback from them and then scale up to 200 in January next year,” Goh explained. &nbsp;“We’d like to check out whether the business model we’ve come up with actually works. We want to show that we can have something of good quality and still bring it out to the market at a price that people find accessible.</p> <p>“Eventually we’d like a sustainable model that can be deployed or adapted elsewhere in the world,” she said.</p> <h2><a href="http://www.impactcentre.ca/light2015">Read more about the International Year of Light</a></h2> <p><img alt="photo of overhead light not turned on" src="/sites/default/files/2015-11-03-light-off.jpg" style="width: 625px; height: 417px; margin: 10px 25px;"></p> <p>&nbsp;</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> <div class="field field--name-field-picpath field--type-string field--label-above"> <div class="field__label">picpath</div> <div class="field__item">sites/default/files/2015-11-03-light-impact.jpg</div> </div> Thu, 05 Nov 2015 06:52:50 +0000 sgupta 7406 at Fiat lux: what do you get when you combine perovskite and colloidal dots? /news/fiat-lux-what-do-you-get-when-you-combine-perovskite-and-colloidal-dots <span class="field field--name-title field--type-string field--label-hidden">Fiat lux: what do you get when you combine perovskite and colloidal dots? </span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span>sgupta</span></span> <span class="field field--name-created field--type-created field--label-hidden"><time datetime="2015-07-17T06:07:14-04:00" title="Friday, July 17, 2015 - 06:07" class="datetime">Fri, 07/17/2015 - 06:07</time> </span> <div class="clearfix text-formatted field field--name-field-cutline-long field--type-text-long field--label-above"> <div class="field__label">Cutline</div> <div class="field__item"> Riccardo Comin (left) and Xiwen Gong combined two different materials to create new hyper-efficient light-emitting crystal (photo by Marit Mitchell)</div> </div> <div class="field field--name-field-author-reporters field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/authors-reporters/marit-mitchell" hreflang="en">Marit Mitchell</a></div> </div> <div class="field field--name-field-author-legacy field--type-string field--label-above"> <div class="field__label">Author legacy</div> <div class="field__item">Marit Mitchell</div> </div> <div class="field field--name-field-topic field--type-entity-reference field--label-above"> <div class="field__label">Topic</div> <div class="field__item"><a href="/news/topics/breaking-research" hreflang="en">Breaking Research</a></div> </div> <div class="field field--name-field-story-tags field--type-entity-reference field--label-hidden field__items"> <div class="field__item"><a href="/news/tags/lighting" hreflang="en">Lighting</a></div> <div class="field__item"><a href="/news/tags/solar" hreflang="en">Solar</a></div> <div class="field__item"><a href="/news/tags/light" hreflang="en">Light</a></div> <div class="field__item"><a href="/news/tags/led" hreflang="en">LED</a></div> <div class="field__item"><a href="/news/tags/international" hreflang="en">International</a></div> <div class="field__item"><a href="/news/tags/engineering" hreflang="en">Engineering</a></div> <div class="field__item"><a href="/news/tags/collaboration" hreflang="en">Collaboration</a></div> <div class="field__item"><a href="/news/tags/research" hreflang="en">Research</a></div> <div class="field__item"><a href="/news/tags/features" hreflang="en">Features</a></div> </div> <div class="field field--name-field-subheadline field--type-string-long field--label-above"> <div class="field__label">Subheadline</div> <div class="field__item">U of T researchers engineer hybrid solar-power crystal that opens new frontiers in high-efficiency lighting</div> </div> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>It’s snack time: you have a plain oatmeal cookie, and a pile of chocolate chips. Both are delicious on their own&nbsp;but if you can find a way to combine them smoothly, you get the best of both worlds.</p> <p>Researchers in the Ƶ's&nbsp;<a href="http://www.ece.utoronto.ca/">Edward S. Rogers Sr. Department of Electrical &amp; Computer Engineering </a>used this insight to invent something totally new: they’ve combined two promising solar cell materials together for the first time, creating a new platform for LED technology.&nbsp;</p> <p>The team designed a way to embed strongly luminescent nanoparticles called colloidal quantum dots (the chocolate chips) into perovskite (the oatmeal cookie). Perovskites are a family of materials that can be easily manufactured from solution, and that allow electrons to move swiftly through them with minimal loss or capture by defects.&nbsp;</p> <div style="float: left; margin: 5px 15px 10px 0; width: 300px"><img alt src="/sites/default/files/2015-07-17_DotsinPerovskite_Glowing1_square-300.gif" style="width: 300px; height: 300px;"> <p style="margin-top:0">A glowing quantum dot seamlessly integrated into a perovskite crystal matrix (Image: Ella Marushchenko).</p> </div> <p>The work was&nbsp;published July 15&nbsp;in <a href="http://www.nature.com/nature/journal/v523/n7560/full/nature14563.html">the international journal <em>Nature</em></a>.</p> <p>“It’s a pretty novel idea to blend together these two optoelectronic materials, both of which are gaining a lot of traction,” said&nbsp;<strong>Xiwen Gong</strong>, one of the study’s lead authors and a PhD candidate working with Professor <strong>Ted Sargent</strong>. “We wanted to take advantage of the benefits of both by combining them seamlessly in a solid-state matrix.”</p> <p>The result is a black crystal that relies on the perovskite matrix to ‘funnel’ electrons into the quantum dots, which are extremely efficient at converting electricity to light. Hyper-efficient LED technologies could enable applications from the visible-light LED bulbs in every home, to new displays, to gesture recognition using near-infrared wavelengths.</p> <p>“When you try to jam two different crystals together, they often form separate phases without blending smoothly into each other,” said&nbsp;<strong>Riccardo Comin</strong>, a post-doctoral fellow in the Sargent Group.</p> <p>“We had to design a new strategy to&nbsp;convince these two components to forget about their differences and to rather intermix into forming a unique crystalline entity.”&nbsp;</p> <p>The main challenge was making the orientation of the two crystal structures line up, called heteroexpitaxy. To achieve heteroepitaxy, Gong, Comin and their team engineered a way to connect the atomic ‘ends’ of the two crystalline structures so that they aligned smoothly, without defects forming at the seams.</p> <p>“We started by building a nano-scale scaffolding ‘shell’ around the quantum dots in solution, then grew the perovskite crystal around that shell so the two faces aligned,” explained coauthor <strong>Zhijun Ning</strong>, who contributed to the work while a post-doctoral fellow at UofT and is now a faculty member at ShanghaiTech.</p> <p>The resulting heterogeneous material is the basis for a new family of highly energy-efficient near-infrared LEDs. Infrared LEDs can be harnessed for improved night-vision technology, to better biomedical imaging, to high-speed telecommunications.</p> <p>Combining the two materials in this way also solves the problem of self-absorption, which occurs when a substance partly re-absorbs the same spectrum of energy that it emits, with a net efficiency loss.</p> <p>“These dots in perovskite don’t suffer reabsorption, because the emission of the dots doesn’t overlap with the absorption spectrum of the perovskite,” Comin said.</p> <p>Gong, Comin and the team deliberately designed their material to be compatible with solution-processing, so it could be readily integrated with the most inexpensive and commercially practical ways of manufacturing solar film and devices.</p> <p>Their next step is to build and test the hardware to capitalize on the concept they have proven with this work.</p> <p>“We’re going to build the LED device and try to beat the record power efficiency reported in the literature,” Gong said.</p> <p>This work was supported by the Ontario Research Fund Research Excellence Program, the Natural Sciences and Engineering Research Council of Canada (NSERC), and the King Abdullah University of Science &amp; Technology (KAUST).</p> </div> <div class="field field--name-field-news-home-page-banner field--type-boolean field--label-above"> <div class="field__label">News home page banner</div> <div class="field__item">Off</div> </div> <div class="field field--name-field-picpath field--type-string field--label-above"> <div class="field__label">picpath</div> <div class="field__item">sites/default/files/2015-07-16-LED-researchers.jpg</div> </div> Fri, 17 Jul 2015 10:07:14 +0000 sgupta 7153 at