9:00 AM - 9:15 AM
[15a-302-1] EDMR Monitoring of Electron-Hole Pairs in Operating Organic Light Emitting Diodes
Keywords:OLED, electron hole pair, EDMR
In normal operation of organic light emitting diodes (OLEDs), electrons and holes combine to form excitons and emission, called electroluminescence (EL), occurs by the transition of singlet excitons to the ground state. Carrier pairs, existing as intermediate states between free carriers and excitons, are significant elements to determine the efficiency of OLEDs and believed to be the origin of magnetoresistance effects in organic semiconductors. In this study, we have carried out electrically detected magnetic resonance (EDMR) and electroluminescence detected magnetic resonance (ELDMR) experiments for polymer LEDs and explored behavers of carrier pairs by analyzing voltage dependences of EDMR intensity, ELDMR intensity, current density and EL intensity.