Preparation and operating characteristics analysis of high-speed iron phthalocyanine organic phototriode

Abstract

The structure of Cu/FePc/Al/FePc/Cu vertical structure organic bipolar junction triode (VOBJT) is prepared by vacuum vapour deposition and magnetron sputtering process, using the photosensitive organic semiconductor material iron phthalocyanine (FePc) as the organic layer. The experiment results show that the device's output current is unsaturated, and the base voltage can effectively regulate the output current. FePc-VOBJT has good optoelectronic characteristics, and the optical response rate can reach R=0.19 A/W. Under the AC base voltage, the cut-off frequency of FePc-VOBJT is fc=10.7 kHz, and the turn-on and turn-off time can reach the microsecond level. When FePc-VOBJT responds to light pulse, the cut-off frequency fc(Light)=2 kHz, and the switch time can reach the millisecond level. Vertical structure dramatically reduces the device's conductive channel length and junction capacitance, which makes the organic semiconductor materials with poor electrical properties expected to be used in high-speed photoelectric sensors.