[18p-E310-1~14] 12.4 Organic light-emitting devices and organic transistors

△ [18p-E310-5] Analysis of TADF-OLED characteristics based on external magnetic field effect (II)

〇Masaki Tanaka¹, Ryo Nagata¹, Hajime Nakanotani¹, Chihaya Adachi¹ (1.OPERA, Kyushu Univ.)

Keywords:TADF, External magnetic field effect, Degradation mechanism

Device characteristics of degraded TADF-OLEDs were analyzed based on external magnetic field effects (MFEs) of the devices. The amplitudes of the changes in the EL intensity under external magnetic field (MEL) of pristine and degraded TADF-OLEDs showed the linear relationship with the change in luminance, which suggests that triplet deactivation processes in the devices correlate with luminance drop under continuous driving. Furthermore, our results suggested the change in the carrier transporting properties of emission layer (EML) in degraded devices results in the exciplex formation between the EML-host and hole-blocking layer and inefficient energy transfer to TADF emitters. This study helps comprehensive understandings of dynamics of exciton in degraded TADF-OLEDs which gives us information of footprints of exciton.