[15p-P9-1~4] 12.2 Characterization and Materials Physics

[15p-P9-4] Characterization of traps in OTFT by DLTS measurements with long filling pulse

〇Takashi Ota¹, Yutaka Tokuda¹, Anan Hiroo², Katou Tetsuya², Katayama Masayuki² (1.Aichi Inst. of Tech, 2.DENSO CORP)

Keywords:DLTS, OTFT

We have characterized density of trap states (trap DOS) in organic thin film transistors (OTFTs) by using DLTS with extremely longer filling times up from 1ms to 1000 s. DLTS measurements are performed by applying the gate bias pulse for OTFTs with the source electrode shorted to the drain electrode. The broad isothermal DLTS spectra are observed, indicating continuously energy distribution of trap states. It is found that the longer filling times are needed to saturate DLTS signals for traps with longer emission time constants, i.e., deeper traps. This might be ascribed to fewer holes available to fill traps in OTFTs. This result will be discussed in connection with the effect of bias stress on the TFT characteristics.