| Organic Electrochemical Transistor（OECT）has received a lot of attention and it has a promising future in the fields of intelligent medical diagnosis,bio-signal sensing,neuromorphic computing,and digital logic circuits due to its high transconductance,low voltage,high capacitance,and compatibility with the aqueous environment.In this work,multilayer porous polymer films are applied to the channel of flexible stretchable OECT devices,which have the advantages of high transconductance,high on current,and high stretchability compared with the conventional single-layer dense film OECT devices.The research of this work is divided into two main parts as follows:（1）Porous films were prepared to offer a general and simple strategy for balancing organic electrochemical transistors’optimizations of redox chemistry,active layer electronic transport,and ion doping/dedoping.Here I demonstrate a universal three-dimensional integrated approach that simultaneously achieves both enhanced transconductance and mechanical stretchability via constructing a multilayer breath-figured porous polymer transistor channel.The formed multilayer elastic porous structure provides efficient and tunable ionic-electronic coupling and transport pathways,while also introducing immunity towards mechanical tensile deformation.Remarkably,an obvious increase in transconductance[from 10.05 m S（2.13 m S）to 29.23 m S（7.38 m S）for Pg2T-T（P3HT）]is acquired by assembling the OECT porous channel from a single layer to a 3D trilayer.Moreover,mechanical stretchability as high as 40%for Pg2T-T and60%for P3HT,is obtained with more than 21%transconductance retained.Furthermore,high transconductance（9.34 m S and 0.92 m S for Pg2T-T and P3HT,respectively）are maintained after 600 stretching cycles（20%and 30%tensile strains for Pg2T-T and P3HT,respectively）.Overall,the 3D stretchable porous structure provides an effective strategy to enhance stretchability and electrical performance for OECTs,as well as opens possibilities for other electronics where both stretchability and a large surface-to-volume ratio are needed.（2）An ion gel layer was introduced to obtain an effective reduction of the hysteresis increase in the hydrophobic multilayer porous polymer active layer.A rigid device with the structure of substrate（Si/Si O2）/source-drain electrode（Au）/multilayer porous polymer active layer（P3HT/SEBS or Pg2T-T/SEBS）/ionic gel layer（PS-PEO-PS:[EMIM][TFSI]:ethyl acetate）/electrolyte（PBS）/gate electrode（Ag/Ag Cl）was designed.It was verified that the ion gel layer can effectively reduce the hysteresis of P3HT-based OECT devices,and a 50%hysteresis reduction was achieved in the 3-layer porous P3HT-based OECT devices.In summary,this thesis uses the high surface-to-volume ratio of a three-dimensional multilayer porous structure to enhance the ion doping/dedoping process,and through the hole deformation to release stress and multilayer connection to ensure the carrier circulation,to achieve the simultaneous enhancement of the electrical performance and stretchability of stretchable OECT devices.And the use of an ion gel layer to reduce the device hysteresis. |
