1. Fabrication of Organic Field Effect Transistor OFET Nano Conducting Polymer and Applications as Urea Sensor Presented by Manal.Z. Rajab Under supervision Dr. Kareema M. Ziadan Republic Of Iraq Ministry of Higher Education And Scientific Research University Of Basrah College Of Science Physics Department

2. The aim of Project Preparation nano conducting polymers Physical properties of preparation materials Characterization of preparation materials Fabrication and Study physical properties of OFET Applications as urea sensor Preparation nano composite conducting polymers Preparation nanoblend conducting polymers Preparation active layer of FET

3. Conjugated Polymers Conjugated polymers (CPs), also known as conducting polymers, are polyunsaturated compounds. Important properties Organic Semiconductors conducting polymers must have an unusual structure. Polymers with conjugated π-electron (system have C=C conjugated bonds) unusual electronic properties such as low energy optical transition. They are highly Fluorescent and are readily soluble. Excitons migrate along the conjugated backbone Conducting polymers are (almost) all conjugated pi Systems ( π-electrons) are delocalized

4. Undoped doped Bipolaron bipolaron states polaron Conducting Mechanism

5. P-Doing N-Doping Doping in Polymers

6.  Electrochemical polymerization  Chemical polymerization  Photochemically initiated polymerization  Enzyme-catalyzed polymerization  Polymerization employing electron acceptors The Polymerization Methods

7. Chemical Polymerization The solvent The monomer Polymerization Temperature Nature of the acid (HA) Nature of the oxidant

8. Active Materials Organic Materials POT-HCLPOT-DBSA Nanocomposite Conducting Polymers POT- HCL/MWCN T PEDOT:PSS /MWCNT Nanoblend Conducting Polymers POT-HCL:PEDOT:PSS POT-HCL /MWCNT:PEDOT: PSS

9. Poly (o-toluidine)/ POT  Poly(o-toluidine) (POT) is a derivative of polyaniline that contains–CH3 group in the ortho position of the aromatic ring of aniline monomer.  Poly(o-toluidine) has emerged as a promising material for numerous commercial applications in different areas because of its good environmental stability, ease of processibility, and relatively low cost.

10. Monomer O-Tolidine dissolve in 1M/HCL Drop APS in 1M/HCL At (0-5C) on stirrer Solution is a dark green Filtered and Washed with ethanol and DI water three times. Dried at (60-80C) for 12 hours POT-HCL Powder POT-HCL POT-HCL add Ammonia and Remains 8 hours, then dried to transform POT-DBSA Powder

11. poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)  PEDOT can be polymerized from 3,4- ethylenedioxy thiophene (EDOT) Chemically or electrochemically.when polymerization is carried out in the presence of aqueous polyelectrolyte poly(styrene sulfonate)(PSS) it becomes water dispersible which is stable,easy to process, with good film forming properties,and with high visible light transmittance.  PEDOT has poor solubility in water and organic solvents. The solubility can be improved by using water-soluble polyelectrolyte, such as PSS (poly-(styrene sulfonic acid)) which is dissolved into PEDOT to form a PEDOT: PSS aqueous

12. Multi Wall Carbon nanotubes Composite with Conducting Polymer Functionalization of CNTs involves the generation of chemical moieties on their surface that can improve the solubility and processibility. the use of a 3:1 concentrated H 2 SO 4 / HNO 3.

13. FTIR Analysis POT -DBSAFTIR Analysis POT-HCL

14. FTIR for MWCNT Before and After Functionalised MWCNT f-MWCNT

15. FTIR for PEDOT:PSS and nanocomposite with MWCNT

16. XRD of POT-DBSA and POT-HCL in NMP/ XRD of f-MWCNT

18. XRD for Nanocomposite for PEDOT:PSS/MWCNT

20. Characterization (FE-SEM) FESEM Results for POT-DBSA in NMP FESEM for POT-HCL in NMP

21. FESEM for nanocomposite POT-HCL /MWCNT

25. The Electrical Conductivity The polymer (POT) SolventsConductivity (σ) (S/ Cm) POT-DBSAChloroform0.380*10 -2 POT-DBSAFormic-acid0.190*10 -2 POT-DBSAToluene0.430*10 -3 POT-DBSAMeta-cresol0.230*10 -3 POT-DBSANMP0.0202*10 -4

28. The System of Devices I-V Curves

29. The Electrical properties The Conductivity for POT-HCL (ITO glass Substrate) The DC conductivity of the thin films collected is investigated using Two-point measurements on two locations on the sample (lab view 2018). The solution (POT-HCL) was deposited on ITO.The conductivity values are calculated from the current via the equation:

31. I-V for f-MWCNTI-V for POT-HCL in NMP

32. I-V for Nanocomposite POT-HCL /MWCNT

33. Table (3) The Electrical conductivity,The Resistivity,and the activation energy for the conducting polymers Materialsσ (s/cm)R (Ω)The Activation Energy(Ea) f-MWCNT in DI water10.971822.40.48 POT-HCL in DMSO0.187*10 -1 1.0695*10 +6 1.705 POT-HCL in NMP0.3*10 -2 5.96745*10 +6 0.306 POT+1 % MWCNT0.01391.43543*10 +6 0.258 POT+3 % MWCNT0.393852461.20.19 POT+5 % MWCNT0.571946273.50.25 POT+7 % MWCNT0.896122361.50.31

34. I-V for Nanocomposite PEDOT:PSS/MWCNT

35. Table (4) The Electrical conductivity,The Resistivity,and the activation energy for the conducting polymers (PEDOT: PSS)/ MWCNT (wt.%) σ (s/cm)R (ohm)Activation Energy (eV) f-MWCNT only10.971822.40.481.21 0.01wt%6.72951.10.35 0.1wt%11.341771.920.14 2.5wt%24831.1130.30 4wt% 26.2768.6640.115 5wt%36.6498.390.091 7.5wt%11.721706.330.31 10wt%3.146356.40.64 PEDOT:PSS only 4.443238.10.48

36. The Optical properties for Conducting polymer The Optical properties for POT-DBSA

37. The Optical properties for POT-HCL

38. Organic Field Effect Transistors  Field-effect transistors comprising organic semiconductors are called organic field-effect transistors (OFETs). An OFET, which typically operates as a capacitor, is composed of three basic elements (i) a semiconductor film or active layer, (ii) an insulating layer or dielectric layer, (iii) three electrodes consisting of source, drain, and gate.  a semiconductor film connects two of the metal electrodes, namely the source (S) and the drain (D), and the third electrode or the gate is separated from the semiconductor film by the gate insulator (dielectric) layer. The distance between the source and the drain is called the channel length (L), and the transverse dimension of the FET is the channel width (W).

40. OFET geometry Figure (). OFET geometry: (a) Top-gate bottom-contact. (b) Top-gate top-contact. (c) Bottom-gate bottom-contact. (d) Bottom-gate top-contact.

41. The System of Devices for OFET

42. The Field Effect Transistor substrate

43. Figure show characterization of P-type OFET by (a)out put curves,(b)Transfer Curves

48. Table (5) Device parameters OFET of POT/HCl based devices (L=50µm, W=0.3mm) The material V th (Volt) I on /I off µ Lin (cm 2 /VS) µ sat (cm 2 /VS) POT/HCL33.71.106*10 1 7.9*10 1 3.71*10 -1 POT/HCL+1%MWCNT33.31.529*10 1 10.05*10 1 3.17 POT/HCL+3%MWCNT31.972.6*10 2 15.8*10 2 18.8 POT/HCL+5%MWCNT30.96.4*10 2 17*10 2 12.8 POT/HCL+7%MWCNT31.351.783.188*10 2 7.685*10 3

49. Urea biosensors based on organic conducting polymers

50. Polymer in sensor applications 1) Gas sensor 2) PH sensor 3) Ion selective sensors 4) Chemical sensors 5) Humidity sensor 6) Enzyme sensor 1) Non-covalent enzyme immobilization.  Direct physical adsorption.  Enzymes adsorbed onto the CNTs functionalized with polymers.  Enzymes adsorbed onto the CNTs functionalized with biomolecules.  Enzymes adsorbed onto CNTs with assistance of surfactants.  Layer-by-layer technique for immobilization of enzymes.. 2)Covalent linking.  Direct covalent linking enzymes onto CNTs.  Covalent attachment of enzymes onto CNTs with linking molecules. Methods of immobilization

51. UREA BIOSENSORS

52. Sensitivity of OFET Urea Enzyme Sensors  Enzyme field-effect transistors (EnFETs) are miniaturized biosensors with an additional immobilized enzyme layer coating on the surface of gate dielectrics of a FET. Those additional layers were fabricated on the supporting materials with entrapped enzyme coatings. Most biological molecules such as enzymes, receptors, antibodies, cells etc. have very short lifetimes in solution phase and thus they have to be fixed in a suitable matrix.  we introduce design and fabrication for bio molecular recognition and its transduction to electrical signals, as well as their application to field-effect transistors for bio molecular sensing. So-called (bio- FETs).

53. 1) OFET as Enzyme Sensor

54. 2) Resistivity as Enzyme Sensor

55. Resistivity Sensors

56. Nanocomposite POT/MWCNT Sensitivity S Relative Response ΔR % POT+MW1%1.3626.9 POT+MW 3%3.3770.35 POT+MW5%8.6788.4 POT+MW7%5.3881

57. Conclusion 1) preparation active layer like nano conducting polymer,nanocomposite with MWNCT +CPs,and nanoblend to improvement the properties of OFET 2)like nano conducting polymer,nanocomposite with MWNCT +CPs,and nanoblend. These active layer 3) MWCNT injection is responsible for an increase in electrical conductivity. Ea is small for high conductivity and large for small conductivity. 4)Fabrication numbers of OFETs for different active layer 5)The electrical measurement found the highest electrical conductivity by using chloroform solvent 0.38*10-1 s/cm after that Formic-acid, Toluene, and lower conductivity at meta-cresol 0.23*10-4 s/cm. 6) PEDOT:PSS +MW 4% is better electrical conductivity and clearly FESEM 7)POT-HCL +MW5% is better relative response and sensitivity.

58. Originality of the Study 1)Studying the effect of the solvents on the electrical properties of POT-DBSA,POT-HCL. 2)Synthesis new nanoblend conducting polymers 3)Fabrication new organic field effect transistor from new active material 4)Synthesis new resistivity sensor based on urea enzyme by using nanocomposite POT-HCL/MWCNT. 5)Fabrication new sensor by using OFET as Enzyme FET.

62. Thank You For Your Listening