BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:Bigger Picture Talks with Professor Chihaya Adachi: The past\, pre sent and future prospects of OLEDs - Professor Chihaya Adachi\, Center for Organic Photonics and Electronics Research\, Kyushu University DTSTART:20221208T160000Z DTEND:20221208T170000Z UID:TALK193334@talks.cam.ac.uk CONTACT:Ellie Hall DESCRIPTION:"Register to attend":https://www.eventbrite.co.uk/e/bigger-pic ture-talks-at-ceb-with-professor-chihaya-adachi-tickets-473243422817\n\nOu r departmental seminar series\, Bigger Picture Talks\, runs throughout the academic year\, inviting thought-leaders from across the world driving si gnificant advances in our impact areas of energy\, health and sustainabili ty to share and discuss their work with us.\n\n*Abstract*\n\nThrough the e xtensive R&D of organic light-emitting diodes (OLEDs) for more than 30 yea rs\, plenty of well-elaborated novel organic optoelectronic materials and device architectures have been extensively developed\, resulting in the un ique commercial utilization of OLEDs for cutting-edge smartphones\, large- area TVs\, and further new future display applications by taking advantage of light-weight and flexibility. From the aspect of materials science\, t he creation of novel light-emitting materials in OLEDs has been the centra l issue aimed at high electroluminescence quantum efficiency. Starting fro m the development of conventional fluorescence materials during 1990-2000t h\, the room-temperature phosphorescence and thermally activated delayed f luorescence continuously pioneered the novel possibilities of organic emit ters\, resulted in not only high-performance OLEDs but also enriched organ ic photochemistry. In recent days\, there have been a wide variety of stud ies on TADF-OLEDs because of the unlimited possibilities of TADF molecular design. Further\, hyperfluorescence-OLEDs have been developed since they can realize the compatibility of high efficiency and narrow spectral width \, which is ideal for practical display applications. Here we report our r ecent cutting-edge HP-OLEDs demonstrating high OLED performance by optimiz ing host\, TADF\, and terminal emitter molecules1-3. In particular\, we fo cus on the blue-emission\, which is capable of showing narrow FWHM and hig h EL quantum yield. Blue HP-OLEDs based on two new TEs are fabricated\, re sulting in high external quantum efficiency of over 20%\, high color purit y\, and high brightness. By analyzing the transient PL characteristics of the HP-OLEDs\, we found the presence of efficient FRET between TADF-assist ant dopant and TE molecules. Further\, transient EL analysis confirmed tha t a smaller EHOMO difference between TADF-AD and TE efficiently helps to d ecrease hole trapping inside the emitting layer\, hence resulting in a low er efficiency rolloff and a longer operational device lifetime. This repor t provides a designing principle for a TADF and TE in HP-OLEDs with well-m atched energy levels\, leading to efficient FRET and no significant carrie r trapping.\n\nIn this presentation\, we mention the importance of the cha rge transfer phenomenon in designing high-performance organic light-emitti ng molecules in OLEDs. Also\, CT issues play a crucial role in maximizing the device's operation. Further\, we outlook the prospect of advanced CT t echnologies.\n\n*Bio*\n\nChihaya Adachi is a distinguished professor at Kyushu University and director of Kyushu University’s Center for Organi c Photonics and Electronics Research (OPERA). He is also the director of t he Fukuoka i3 center for Organic Photonics and Electronics Research. Chiha ya Adachi obtained his doctorate in Materials Science and Technology in 19 91 from Kyushu University and held positions at the Chemical Products R&D Center at Ricoh Co.\, the Department of Functional Polymer Science at Shin shu University\, the Department of Electrical Engineering at Princeton Uni versity\, and Chitose Institute of Science and Technology before returning to Kyushu University as a professor.\n\nAdachi’s research combines the areas of chemistry\, physics\, and electronics to advance the field of org anic light-emitting materials and devices from both the materials and devi ce perspectives through the design of new molecules with novel properties\ , the study of processes occurring in individual materials and complete de vices\, and the exploration of new device structures\, and he has co-autho red over 600 research papers. LOCATION:Lecture Theatre 2\, Department of Chemical Engineering and Biotec hnology\, West Cambridge Site END:VEVENT END:VCALENDAR