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Evaluation of Delayed Fluorescence Compounds
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DOR
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20.1001.2.0021079099.1400.8.1.12.2
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نویسنده
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Nasiri Sohrab
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منبع
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كنگره بين المللي رنگ و پوشش - 1400 - دوره : 8 - کنگره بین المللی رنگ و پوشش - کد همایش: 00210-79099 - صفحه:1 -1
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چکیده
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The third generation of organic light emitting diode (oled) emitters comprises organic donor-acceptor systems, as well as transition metal (tm) complexes with small singlet-triplet energy gap δest that lies within the range of thermal energy. because of the small δest, reverse intersystem crossing (risc) from the lowest excited triplet state to the lowest excited singlet state is reasonably done, and thermally activated delayed fluorescence (tadf) is performed, tadf is called e-type delayed fluorescence (df) in the older literature. like phosphorescence oleds (pholeds), tadf-based oleds show an internal quantum efficiency of up to 100%. a disadvantage of many presently available tadf oleds that they share with the pholeds is rather low intrinsic radiative transition rate (kr=106-107 s−1) of the emitters that makes them sensitive to non-radiative decay processes. also, the emission from states with charge-transfer (ct) character typically is rather broad, which is not favorable for application in displays
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کلیدواژه
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Oled ,Tadf ,Emission ,Singlet-Triplet Energy
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آدرس
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Karlstad University, Department Of Engineering And Physic, Sweden, Department Of Mechanical Engineering, Kaunas University Of Technology, Studentu Street, Department Of Mechanical Engineering, Kaunas, Department Of Mechanical Engineering, Kaunas University Of Technology, Studentu Street
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Evaluation of delayed fluorescence compounds
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Authors
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Abstract
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The third generation of Organic light emitting diode (OLED) emitters comprises organic donor-acceptor systems, as well as transition metal (TM) complexes with small singlet-triplet energy gap ΔEST that lies within the range of thermal energy. Because of the small ΔEST, reverse intersystem crossing (RISC) from the lowest excited triplet state to the lowest excited singlet state is reasonably done, and thermally activated delayed fluorescence (TADF) is performed, TADF is called E-type delayed fluorescence (DF) in the older literature. Like phosphorescence OLEDs (PHOLEDs), TADF-based OLEDs show an internal quantum efficiency of up to 100%. A disadvantage of many presently available TADF OLEDs that they share with the PHOLEDs is rather low intrinsic radiative transition rate (kr=106-107 s−1) of the emitters that makes them sensitive to non-radiative decay processes. Also, the emission from states with charge-transfer (CT) character typically is rather broad, which is not favorable for application in displays
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Keywords
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OLED ,TADF ,Emission ,Singlet-triplet energy
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