| With the continuous development of science and technology,the disadvantages of traditional inorganic semiconductor devices in terms of production,cost and products are gradually emerging,organic semiconductor devices have a broad development prospect because of their flexibility,low cost and a wide choice of materials.In particular,the devices prepared with photosensitive organic semiconductor materials can be applied to light detection work,light-controlled switches and image sensing fields.In this paper,the organic thin-film diode（OTFD）with Cu/iron phthalocyanine（FePc）/Al structure and the vertical structure organic phototriode（VOPT）with Cu/FePc/Al/FePc/Cu sandwich structure are prepared by vacuum thermal vapor deposition and magnetron sputtering process using the photosensitive organic semiconductor material FePc as the organic layer.This paper reviews the current status of organic solar cells and organic photovoltaic transistors in organic photovoltaic devices at home and abroad,introduces the phthalocyanine metal complexes used in this paper,and the vertical structure of the devices in detail.Characterizing the physical properties of the device films,the experiment results show that the organic films have a crystal structure ofα-FePc and have good light absorption in the near-infrared region.The Al film almost completely covers the organic film in the device,and the Cu film has a larger transmittance of light at 625nm,about 25%.The operating characteristics of FePc-OTFD are experimented,and the results show that the Schottky contact is formed between FePc and Al electrode,and the I-V characteristic curve is rectified,the electric field intensity inside the depletion layer Eq=5.2×107 V/m,the series resistance rs=434.26Ω.The obvious photovoltaic effect under light illumination,the filling factor FF=40.54%,and the power conversion efficiency PCE=0.17%.The operating characteristics of FePc-VOPT are experimented,and the results show that the output current of the device is unsaturated,the base voltage can effectively regulate the output current.In dark state,the threshold voltage of the device is about VTH=0.6 V,the current amplification can reachβI=3.04×103,the carrier mobilityμ=1.54×10-5 cm2.The device has good optoelectronic characteristics,optical response rate up to R=0.19 A/W.The results of AC small signal dynamic experiment show that the cut-off frequency of FePc-VOPT is fc=10.7 k Hz,and the turn-on and turn-off time can reach microsecond level;the cut-off frequency of device response to light pulse signal can reach fc（Light）=2 k Hz,and the turn-on and turn-off time can reach millisecond level.In this paper,a vertical structure is used to shorten the conductive channel length of the device,analyze the physical parameters of the device by experimenting the electrical properties and photosensitive characteristics of the device,and analyze the mechanism of the effect of light on the device,so as to provide an experimental basis for the application of inexpensive organic semiconductor materials in the field of high-speed optoelectronic sensors. |
