Research And Fabrication Of Organic Field-effect Transistors And Organic Photo Field-effect Transistors

Organic Field-effect Transistors(OFETs) have attracted considerable attention due totheir prominent features for realizing low-cost, large-area, and mechanically flexible such asdriving active matrix displays, identification cards, sensing devices and electronic paper.Theresearch of OFETs have important application value and scientific significance.Firstly, the different development stages，the existing problem and the development trendof the OFETs have been summarized. And then structure of the devices, electrode material,organic semiconductor material and the dielectric material were introduced. According to theresearch status and some existing issues of OFETs, we fabricate OFETs using differentdielectrics and organic photosensitive device. The research contents is summarized asfollows:(1) C60-based OFETs with polyvinyl alcohol(PVA) dielectric are fabricated. Thedevices exhibit typical N-channel characteristics. Furthermore, C60-based OFETs usingdifferent consistences of dielectrics are fabricated. Comparing with different consistences,60mg/ml is optimum. The effective field-effect mobility, threshold voltage and on/off ratio aredetermined to be4.6×10-2cm2/V·s,20V and103, respectively. The performance of the devicesare analyzed.(2) C60-based OFETs, using a biomaterial, albumen, as the gate dielectrics are fabricated.The effective field-effect mobility and the threshold voltage are determined to be2.59cm2/Vsand1.25V, respectively. The OFETs with albumen dielectric demonstrate reasonable electricalcharacteristics and typical N-channel characteristics.The high performances of the OFETs areattributed to the high dielectric constant and smooth surface roughness. Furthermore, thethermal treatment conditions of the albumen dielectric and the surface topography areresearched. The high performances of the OFETs are attributed to the high dielectric constantand smooth surface roughness. The albumen from chicken eggs can be a very promisingdielectric material for a low-cost solution processed OFETs and widely used in practice.(3) Pentacene-based OPTs are fabricated. The OPTs using Al S/D electrodes modified byinserting a transition metal oxide (V2O5) layer and Pentacene as the organic semiconductorlayer. The influence of illumination on the device performance are researched. Beforeillumination the effective field-effect mobility, threshold voltage and on/off ratio of the deviceare0.101cm2/V·s,24V and102. After illumination the effective field-effect mobility, thresholdvoltage and on/off ratio of the device are0.187cm2/V·s,20V and102. In addition, theperformances of the devices is changing and photoresponse and photocurrent on/off ratioare18.9mW/A and0.85, respectively. This research is good basis for functional OFETs.