[11p-S222-1~13] 12.4 Organic light-emitting devices and organic transistors

[11p-S222-10] Operando observation of charge carrier behavior in the highly-efficient blue-emitted OLED devices using time-resolved electric field-induced doubly-resonant sum-frequency generation spectroscopy

〇Takayuki Miyamae¹, Tomoya Sato¹, Hiroshi Ohata², Tetsuo Tsutsui² (1.AIST, 2.CEREBA)

Keywords:Blue-emitted OLEDs, degradation, sum-frequency generation

Recently, we have succeeded in probing buried organic layers in OLEDs during operation by electric-field-induced sum-frequency generation (EFI-SFG) under doubly-resonant condition. When a strong DC electric field is applied to the organic device, it leads to a significant increase in the SFG intensity produced by the internal carriers. Furthermore, we report the direct observation of the carrier behavior in OLEDs by time-resolved EFI-SFG technique. The use of this new technique allows us to observe the carrier behavior at the organic interfaces varied with time in response to the applied pulse bias voltage non-destructively. In this paper, we will report the charge accumulation and transport mechanisms of the highly-efficient fluorescent blue OLEDs under the operation.