Huang, JYJYHuangHung, HCHCHungHsu, KCKCHsuChen, CHCHChenLee, PHPHLeeLin, Hung-YiHung-YiLinLin, BYBYLinLeung, MKMKLeungChiu, TLTLChiuLee, Jiun-HawJiun-HawLeeFriend, RHRHFriendWu, YRYRWu2023-03-092023-03-0920232513-03902200633https://scholars.lib.ntu.edu.tw/handle/123456789/629067In this study, a steady state and time-dependent exciton diffusion model including singlet and triplet excitons coupled with a modified Poisson and drift-diffusion solver to explain the mechanism of hyper triplet–triplet fusion (TTF) organic light-emitting diodes (OLEDs) is developed. Using this modified simulator, various characteristics of OLEDs, including the current-voltage curve, internal quantum efficiency, transient spectrum, and electric profile are demonstrated. This solver can also be used to explain the mechanism of hyper-TTF-OLEDs and analyze the loss from different exciton mechanisms. Furthermore, we perform additional optimization of hyper-TTF-OLEDs that increases the internal quantum efficiency by ≈33% (from 29% to 40%).endevice modeling; organic light-emitting diodes; triplet- triplet fusion; ACTIVATED DELAYED FLUORESCENCE; CHARGE-TRANSPORT; EFFICIENCY; MOBILITY[SDGs]SDG7journal article10.1002/adts.2022006332-s2.0-85143914780WOS:000896711800001https://api.elsevier.com/content/abstract/scopus_id/85143914780