tesi R. Miscioscia.pdf - EleA@UniSA

More documents

Recommendations

Info

$3Eterov e)ce(te/rou sofo\v to/ te pa/lai to/ te nu=n. Ou ... - EleA@UniSA$

72 State of the Art figure 42: effect of annealing process on a conductive ink of Au-NP [41]. 2.7.2 Polymeric electrodes A big limit for flexibility and transparency of organic circuits is the presence of metallic contacts and inorganic oxides. Thus, materials like PEDOT:PSS and doped Polyaniline are tested to fabricate logic circuits with OTFTs, to obtain devices with both organic semiconductor and Source and Drain organic/polymeric contacts, also because in this way printing 1 and spin-coating deposition techniques can be applied. However, these materials show high resistivity and contact resistance, and tend to create non-ohmic contacts. 2.7.2.1 PSS:PEDOT Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS), is a material widely employed in Organic Electronics, 1 Printing techniques: • Digital o IJP o Thermal • Gravure printing (a cylindrical metallic surface presents pits which can contain very small quantities of ink to release on the substrate to print) • Offset lithography • Flexography
Chapter 2 73 in particular in OLEDs [50][51][52] as a Hole Injection Layer (HIL), thanks its high work-function. One of its advantages is a rather high conductivity (about 1 S/cm, as shown in [53]) and low sheet resistance. Another important characteristic is that it is water soluble, which gives the direct opportunity to use it as an ink for IJP systems, as done in [54]. Moreover, recent technological advancements have succeeded in using it for OTFTs with self-aligned contacts [55]. In this paper, published in Nature on 2007, authors report on an OTFT with polymeric Gate of PEDOT:PSS, applying a process called SAP (Self- Aligned Printing), already shown in [56], obtaining scalable submicron structures. Source and Drain contacts are produced in the following way: a first structure (for example, Source) of PEDOT:PSS is deposited through IJP and then its surface energy is reduced using a suitable process; in this way, a second structure (Drain) deposited to partially cover the previous one, doesn’t wet the surface and moves at the side, forming automatically a gap to create the device channel (see figure 43). figure 43: self-aligned structures for OTFTs, with Gate of sub-micron length, are obtained modifying the wettability of a drop of PEDOT:PSS.
Page 1 and 2:
Università degli Studi di Salerno
Page 3 and 4:
Acknowledgments It is a pleasure to
Page 5 and 6:
In loving memory of my uncle, Profe
Page 7 and 8:
Introduction Nowadays, it has becom
Page 9 and 10:
Introduction 3 The drawbacks of org
Page 11 and 12:
Introduction 5 Artificial Skin (OTF
Page 13 and 14:
Introduction 7 structure has been d
Page 15 and 16:
Chapter 1 Working principles An Org
Page 17 and 18:
Chapter 1 11 1.1 A model for DC beh
Page 19 and 20:
Chapter 1 13 hp. 4) Decoupling betw
Page 21 and 22:
Chapter 1 15 figure 2: integration
Page 23 and 24:
Chapter 1 17 eq. 11 − = Then, bei
Page 25 and 26:
Chapter 1 19 The formula in eq. 18
Page 27 and 28: Chapter 1 21 and behaves as a resis
Page 29 and 30: Chapter 1 23 eq. 22 I DS = μ C ins
Page 31 and 32: Chapter 1 25 In eq. 27, kB is the B
Page 33 and 34: Chapter 1 27 eq. 30 · Thu
Page 35 and 36: Chapter 2 A survey on the state of
Page 37 and 38: Chapter 2 31 emphasizing the role p
Page 39 and 40: Chapter 2 33 Only after those years
Page 41 and 42: Chapter 2 35 In fact, usually the m
Page 43 and 44: Chapter 2 37 Examples of top-gate b
Page 45 and 46: Chapter 2 39 deposition process of
Page 47 and 48: Chapter 2 41 region is patterned by
Page 49 and 50: Chapter 2 43 figure 11: Non-Relief-
Page 51 and 52: Chapter 2 45 factor analysing, in p
Page 53 and 54: Chapter 2 47 In literature results,
Page 55 and 56: Chapter 2 49 It is clear that the c
Page 57 and 58: Chapter 2 51 In figure 17 the impro
Page 59 and 60: Chapter 2 53 figure 19: OFET trans-
Page 61 and 62: Chapter 2 55 figure 22: Comparison
Page 63 and 64: Chapter 2 57 channel and gate in Pe
Page 65 and 66: Chapter 2 59 figure 28: Pentacene b
Page 67 and 68: Chapter 2 61 figure 31: OTFT realiz
Page 69 and 70: Chapter 2 63 materials, the higher
Page 71 and 72: Chapter 2 65 The effect of the barr
Page 73 and 74: Chapter 2 67 figure 36: potential p
Page 75 and 76: Chapter 2 69 From table 2, it is ea
Page 77: Chapter 2 71 thermal-budget treatme
Page 81 and 82: Chapter 2 75 One interesting charac
Page 83 and 84: Chapter 2 77 figure 48: electrical
Page 85 and 86: Chapter 2 79 The research on the OE
Page 87 and 88: Chapter 2 81 photolysis). In this p
Page 89 and 90: Chapter 2 83 [26] Facchetti, Wasiel
Page 91 and 92: Chapter 3 Gate-leakages in polymeri
Page 93 and 94: Gate-leakages 87 determined by XRD
Page 95 and 96: Gate-leakages 89 The results are:
Page 97 and 98: Gate-leakages 91 It has to be consi
Page 99 and 100: Gate-leakages 93 figure 8: Output c
Page 101 and 102: Gate-leakages 95 figure 12: electri
Page 103 and 104: Gate-leakages 97 3.4 Advanced circu
Page 105 and 106: Gate-leakages 99 figure 16: SEM ima
Page 107 and 108: Gate-leakages 101 modeled with a co
Page 109 and 110: Gate-leakages 103 eq. 11 • Shadow
Page 111 and 112: Gate-leakages 105 References [1] R.
Page 113 and 114: Chapter 4 Morphology-mobility relat
Page 115 and 116: Chapter 4 109 insulators to increas
Page 117 and 118: Chapter 4 111 3.2 General device st
Page 119 and 120: Chapter 4 113 Pentacene islands are
Page 121 and 122: Chapter 4 115 For the preparation o
Page 123 and 124: Chapter 4 117 figure 3: PFTEOS:TEOS
Page 125 and 126: Chapter Chapter 4 4 119 (a): (a):
Page 127 and 128: Chapter 4 121 3.4 Device’s charac
Page 129 and 130:
Chapter 4 123 mobility with the dim
Page 131 and 132:
Chapter 4 125 As it can be observed
Page 133 and 134:
Chapter 4 127 eq. 4 Where r
Page 135 and 136:
Chapter 4 129 3.4.3 Thermal charact
Page 137 and 138:
Chapter 4 131 Ea(eV) 0.50 0.45 0.40
Page 139 and 140:
Chapter 4 133 I D (A) 100.0n 80.0n
Page 141 and 142:
Chapter 4 135 μ (cm 2 V -1 s -1 )
Page 143 and 144:
Chapter 4 137 T MN (K) 2400 2200 20
Page 145 and 146:
Chapter 4 139 Such results, supply
Page 147 and 148:
Chapter 4 141 References [1] O. D.
Page 149 and 150:
Chapter 4 143 [26] P. Palestri, D.
Page 151 and 152:
Conclusions In this PhD dissertatio
Page 153 and 154:
Introduction 147 characterizing mor
Page 155 and 156:
Table of acronyms and symbols Symbo
Page 157:
Table of acronyms and symbols _____
show all

tesi R. Miscioscia.pdf - EleA@UniSA

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?