Single emission spectrum measurement enables control of organic LED emission zone giving ultralong device lifetime

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A new single-emission-spectrum measurement technique visualizes organic LED emission zones, enabling device optimization for ultralong lifetimes and high external quantum efficiency.

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Abstract

Abstract Device optimization of light-emitting diodes targets the most efficient conversion of electrically injected charges into emitted light. Where charges recombine and where light is emitted from is known as the emission zone. Determining its form is key to better understanding the physical processes determining device performance. However, a thorough measurement study has not been shown. Here we present an accessible technique to visualize the emission zone in unprecedented detail at all luminescing current densities. Only a single emission spectrum must be measured (at normal direction to the device layers with no additional optics) and compared with the simulated emission spectrum. This method allows physical understanding based, instead of speculative, optimisation of LED device architectures. We demonstrate its impact by examining the device structure – emission zone – lifetime relationships of a thermally activated delayed fluorescence OLED to achieve an ultralong 4500 hour T95 lifetime at 1000 cd/m2 with 20% external quantum efficiency.
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Single emission spectrum measurement enables control of organic LED emission zone giving ultralong device lifetime | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Single emission spectrum measurement enables control of organic LED emission zone giving ultralong device lifetime Rossa Mac Ciarnáin, Hin Wai Mo, Kaori Nagayoshi, Hiroshi Fujimoto, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-614826/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Device optimization of light-emitting diodes targets the most efficient conversion of electrically injected charges into emitted light. Where charges recombine and where light is emitted from is known as the emission zone. Determining its form is key to better understanding the physical processes determining device performance. However, a thorough measurement study has not been shown. Here we present an accessible technique to visualize the emission zone in unprecedented detail at all luminescing current densities. Only a single emission spectrum must be measured (at normal direction to the device layers with no additional optics) and compared with the simulated emission spectrum. This method allows physical understanding based, instead of speculative, optimisation of LED device architectures. We demonstrate its impact by examining the device structure – emission zone – lifetime relationships of a thermally activated delayed fluorescence OLED to achieve an ultralong 4500 hour T95 lifetime at 1000 cd/m2 with 20% external quantum efficiency. Photonics/optics Optics/Lasers Optical Materials and Devices light-emitting diodes light emissions device lifetime Full Text Additional Declarations There is NO Competing Interest. Supplementary Files RossaSuppInfo.pdf Supplementary Information Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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