[16p-P5-1~17] 12.2 Characterization and Materials Physics

[16p-P5-13] Effects of bias stress and light illumination on OTFTs

〇Takashi Ota¹, Yuki Aoki¹, Nishiwaki Kota¹, Yutaka Tokuda¹, Hiroo Anan², Tetsuya Katou², Masayuki Katayama² (1.Aichi Inst. of Tech., 2.DENSO CORP.)

Keywords:Organic semiconducor

We have characterized effects of bias stress and light illumination on OTFTs from the shift of threshold voltage (V_th) and current DLTS measurements. V_th shows a negative shift with bias stress, which indicates the introduction of positively charged species, provably due to trapping of holes. Partial recovery of bias-stress-induced shift of V_th at 300 K is observed due to the thermal emission of holes from filled traps. However, V_th never recovers to its initial one. It is found that complete recovery of bias-stress-induced shift of V_th occurs by blue LED light illumination at 300 K. The complete recovery by light illumination is caused by optical emission of holes from filled traps which never emit holes thermally at 300 K because of their high thermal activation energies. The current DLTS measurements are now being performed to clarify trap distributions which induce bias stress effect.