In above study, the PEDOT: PSS films were successfully improved through heating and stirring and multiple treatment. The sheet resistance of PEDOT: PSS film is 35 ohm/square, and the transmittance of PEDOT: PSS film is 80.1%. In the future works, the conductivity of PEDOT: PSS film will be further improved by using carbon nanotube. The improvement of PEDOT: PSS films will be substituted for ITO electrode as the anode of organic photoelectric devices. The PEDOT: PSS film has a great advantage of mechanical flexibility than the ITO film. Thus, the PEDOT: PSS film can be also applied to flexible organic solar cells and flexible organic light-emitting diodes.
The ultimate goal of the research is “flexible organic optoelectronic components.”
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Figure 2.1 The chemical structure of PEDOT:PSS.
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Figure 2.2 The conductive mechanism reaction of the PEDOT and the PSS.
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Figure 3.1 The Chemical structure of formic acid.
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Figure 3.2 The schematic illustration of cleaned the glass substrates and treated with Oxygen plasma.
d
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Figure 3.3 The schematic illustration of oxygen plasma surface modification.
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Figure 3.4 The schematic illustration ofoptimize the PEDOT:PSS solution by filter andheating and stirring.
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Figure 3.5 The schematic illustration of spin-coating and baked in oven.
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Figure 3.6 The schematic illustration of film rinsed with DI water.
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Figure 3.7 The schematic illustration ofspin-coating and baked in oven.
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Figure 3.8 The schematic illustration of formic acid immerse treatment.
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Figure 3.9 The schematic illustration of formic acid multiple treatment.
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Figure 3.10 The schematic illustration of oxygen plasma patterning.
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Figure 4.1 The schematic illustration of heating and stirring processing comparison to multiple spin-coating processing.
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Figure 4.2 The schematic illustration of structure change by heating and stirring.
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Figure 4.3 The schematic illustration of particle size changed after heating and stirring.
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Figure 4.4 The variation of PEDOT:PSS film thickness and solution amount with time of heating and stirring at 100 °C, 200 rpm.
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Figure 4.5 The variation of transmittance and solution amount with time of heating and stirring at 100 °C, 200 rpm.
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Figure 4.6 The SEM top view images of PEDOT:PSS films heating at 100 °C in different stirring times: (a) 0 min, (b) 10 min, (c) 18 min, (d) 22 min. All the scale in the image are 10 μm.
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Figure 4.7 The EDS image of white particles in SEM images of the PEDOT:PSS films.
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Figure 4.8 SEM top view images of PEDOT:PSS films formed with 65% amount solution after heating at 200 rpm with different temperatures and times: (a) 50 °C, 100min, (b) 100°
C, 22 min and (c) 150 °C, 8.5 min. All the scale in the image are 10 μm.
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Figure 4.9 The AFM topographic images of PEDOT:PSS films heating at 100 °C, 200 rpm with different stirring times: (a) 0 min, (b) 10 min, (c) 18 min, and (d) 22 min. All the images are 1 μm × 1 μm.
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Figure 4.10 The AFM 3D topographic images of PEDOT:PSS films heating at 100 °C, 200 rpm with different stirring times: (a) 0 min, (b) 10 min, (c) 18 min, and (d) 22 min.
All the images are 1 μm × 1 μm.
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Figure 4.11 The AFM adhesion map of PEDOT:PSS films heating at 100 °C, 200 rpm with different stirring times: (a) 0 min, (b) 10 min, (c) 18 min, and (d) 22 min. All the images are 1 μm × 1 μm.
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Figure 4.12 The AFM schematic representation of a force curve, and important events in the measurement of adhesion.
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Figure 4.13 The AFM current images of PEDOT:PSS films heating at 100 °C, 200 rpm with different stirring times: (a) 0 min, (b) 10 min, (c) 18 min and (d) 22 min. All the images are 1 μm × 1 μm.
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Figure 4.14 The current density and longitudinal conductivity depend on time of heating stirring.
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Figure 4.15 The XPS spectra of pristine and solution optimized of PEDOT:PSS films.
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Figure 4.16 The conductivity of PEDOT:PSS film by formic acid treatment with four different methods.
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Figure 4.17 The variation of sheet resistance and transmittance with time of heating and stirring at 100 °C, 200 rpm after formic acid multiple treatment
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Figure 4.18 The UV-Vis-NIR absorption spectroscopy of PEDOT:PSS films with the different method of formic acid treatments.
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Figure 4.19 The XPS sulfur (2p) spectra of PEDOT:PSS films with different treated methods of formic acid.
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Figure 4.20 The XPS oxygen (O) 1s spectra of PEDOT:PSS films with different treated methods of formic acid.
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Figure 4.21 The SEM images of PEDOT:PSS films: (a) pristine, (b) treated with immersing formic acid, (c) treated with dropping formic acid and (d) treated with DAIFA. All the scale bars in the image are 1 μm × 1 μm.
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Figure 4.22 The AFM images of PEDOT:PSS films: (a) pristine, (b) treated with immersing formic acid, (c) treated with dropping formic acid and (d) treated with DAIFA. The images are topographic images. All the images are 1 μm × 1 μm.
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Figure 4.23 The variation of transmittance and sheet resistance with immersion time in DAIFA treatment of PEDOTPSS film
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Figure 4.24 The schematic illustration of PEDOT:PSS film transmittance after formic acid treatment.
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Figure 4.25 The schematic illustration of PEDOT:PSS film after DAIFA treatment.
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Figure 4.26 The results of PEDOT:PSS film pattern by oxygen plasma.
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Table 4.1 The costs in processing of heating and stirring compared with the multilayer film.
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Table 4.2 The solution amount and solution concentration of PEDOT:PSS with time of heating and stirring at 100 °C, 200 rpm.
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Table 4.3 The heating temperatures corresponds to the heating time stirring at 200 rpm to make the 65 % solution amount of PEDOT:PSS solution.
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Table 4.4 The roughness of PEDOT:PSS films corresponds to heating time stirring at 200 rpm, 100 °C
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Table 4.5 The current density and longitudinal conductivity in PEDOT:PSS films depend on time of heating stirring.
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Table 4.6 The reduction in film thickness by different treatment method of formic acid.
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Table 4.7 The influence on ratio of PEDOT to PSS in PEDOT:PSS film by different treatment method of formic acid
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Table 4.8 The influence on ratio of PEDOT to PSS in PEDOT:PSS film by different treatment method of formic acid