Fabrication And Performance Of OFETs Based On Composite Semiconductor Layer

With the rapid development of society and economy,due to the single nature of single-component semiconductor layer functional devices,they can not fully meet people’s daily life needs.Therefore,in order to make electronic devices multifunctional,composite semiconductor layers came into being.In this paper,the composite semiconductor layer was prepared by solution blending method,including the preparation of near infrared light detecting composite film by blending dithiophene thickened pyrrole and pyrrole dione polymer with[6,6]phenyl C71 methyl butyrate(PC₇₁BM).A composite semiconductor layer with both tensile and conductive properties was prepared by blending poly（3-hexylthiophene）（P3HT）and styrene-butadiene-styrene block copolymer（SBS）.The charge transport performance of the composite semiconductor layer was further improved by adding P-type dopant copper trifluoromesylate（Cu（OTf）₂）into the composite system.The main contents are as follows:（1）The study investigated the effect of the introduction of benzothiadiazole on the near-infrared light response performance of the dithiophene fused pyrrolidine pyrrolidone polymer/PC₇₁BM heterojunction.At an ultra-low irradiation intensity of 1.8μWcm^-2,the light response of the semiconductor polymer/PC₇₁BM heterojunction containing benzothiadiazole increased from 118AW^-1 to 317AW^-1.The introduction of benzothiadiazole enhanced the interaction between the semiconductor polymer and PC₇₁BM,reduced the scale of microphase separation,It was conducive to the effective separation of excitons and thus had high sensitivity to weak light.（2）The electrical and mechanical properties of the composite semiconductor layer of conjugated polymer P3HT and various types of rubber elastomer SBS/SEBS were studied.When SBS791H was selected as rubber elastomer,mass ratio of P3HT to SBS791H was 1:1,chlorobenzene was selected as solvent,spin coating speed was 2000r/min,spin coating time was 60s,the performance of the transistor was the best:mobility of 1.5×10^-2cm²V^-1s^-1,threshold voltage was 2V,current on-off ratio was 1.3×10³.The maximum stress of the composite semiconductor layer was 2.41Mpa and the maximum strain was 192%.（3）By studying P3HT and Cu（OTf）₂ doped films,it was concluded that P-type dopants can improve the field effect performance of transistors.After adding SBS791H,it was found that under the mass ratio of doping and blending of P3HT:Cu（OTf）₂:SBS791H=100:1:300,there were optimal field effect properties and flexible tensile properties.The corresponding mobility was 8.6×10^-2cm²V^–1s^–1,the threshold voltage was 11V,the current on-off ratio was 28,the Young elastic modulus was 0.64Mpa,the maximum stress was 3.39Mpa,and the maximum strain was 441%.It shows that the composite semiconductor layer has the versatility of being conductive and stretchable.