Solution-processable conductive polymer films

Abstract

The invention relates to conductive polymer compositions and conductive polymer films comprising poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a dopant. The invention further relates to electronic components comprising such conductive polymer films. The invention further relates to methods for producing such electronic components.

Description

[0001] Solution-processable conductive polymer films

[0002] Technical field

[0003] The invention relates to conductive polymer compositions and conductive polymer films comprising poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a dopant. The invention further relates to electronic components comprising such conductive polymer films. The invention further relates to methods for producing such electronic components.

[0004] Background

[0005] Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, commonly abbreviated as PEDOT:PSS, is a well-known conductive polymer usable in organic and printable electronics applications. PEDOT:PSS is largely used as a transparent electrode in, e.g., touchscreens, organic light-emitting diodes, flexible organic solar cells and electronic paper to replace the traditionally used indium tin oxide (ITO).

[0006] Conventional PEDOT:PSS films show sheet resistances of approx. 1-100 kQ / sq. Unfortunately, for some applications such as infrared and X-ray detectors having active layers based on quantum-confined nanocrystals, such conductivity is too low. Furthermore, conventional PEDOT:PSS grades, being acidic, may destroy an underlying nanocrystal film when deposited on top.

[0007] Summary

[0008] An object of the present invention is to overcome the drawbacks appearing in the prior art.

[0009] Another object of the invention is to provide a PEDOT:PSS composition suitable for use in electronic components comprising quantum-confined nanocrystals.

[0010] The invention is characterized by what is defined in the independent claims. Embodiments of the invention are presented in dependent claims.

[0011] The features recited in the dependent claims and the embodiments in the description are mutually freely combinable unless otherwise explicitly stated. The exemplary embodiments presented in this text and their advantages relate by applicable parts to all aspects of the invention, even though this is not always explicitly mentioned.

[0012] A conductive polymer composition is presented. The conductive polymer composition comprises poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), a dopant, and water. PEDOT:PSS is present in the composition typically in an amount of 0.1-10 wt-% of the total weight of the composition. The dopant is present typically in an amount of 0.01-20 wt-% of the total weight of the composition. Water is typically present in the composition in an amount of 70-99.9 wt-% of the total weight of the composition. The composition, in the form of an aqueous polymer solution, typically has a conductivity of 500 S / cm or more, such as 500-5000 S / cm. The advantage of the doped PEDOT:PSS over pristine PEDOT:PSS grades in electronic components comprising quantum-confined nanocrystals lies in increased conductivity of the composition, leading to increased conductivity in films produced from the polymer composition. The polymer composition as presented herein also has an advantage of improving the surface morphology of polymer films produced using the polymer composition. The dopant decreases the surface tension of the polymer composition compared to polymer compositions comprising only pristine PEDOT:PSS, whereby the composition spreads more evenly on a substrate of, e.g., quantum-confined nanocrystals during a solution-based film preparation process. Better spreading of the composition in turn improves the morphology of the forming polymer film.

[0013] A transparent conductive polymer film for electronic components comprising quantum-confined nanocrystals is provided. The polymer film comprises poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a dopant. The film has a sheet resistance of 500 Q / sq or less, such as 50-500 Q / sq. The polymer film has a transmittance of at least 50%, such as 50-100%, preferably 80-100%, at wavelengths from 170 to 2800 nm. The doped PEDOT:PSS has the advantage of improved conductivity compared to pristine PEDOT:PSS grades, while still maintaining an adequate transparency for photodetector applications. The increased conductivity and the high transmittance facilitate the use of the polymer film as a transparent top electrode in electronic components. Thereby, the top electrode production process may be simplified compared to conventional top electrodes (e.g., ITO). The polymer films presented herein may be processed from solution, at ambient conditions, thereby eliminating the need for expensive and complicated vacuum systems.

[0014] An electronic component comprising quantum-confined nanocrystals is provided. A transparent top electrode of the electronic component may be produced using the conductive polymer composition as described herein. Alternatively, the electronic component may comprise the transparent conductive polymer film as provided herein as a transparent top electrode. The doped PEDOT:PSS when used as a transparent top electrode has the advantage of improved conductivity when compared to conventional PEDOT:PSS electrodes.

[0015] A method for producing an electronic component is provided. The method comprises providing an unfinished electronic component; depositing a conductive polymer composition on the unfinished electronic component to provide a conductive polymer layer; patterning the unfinished electronic component; and optionally depositing a transparent top electrode on the patterned unfinished electronic component to connect the component to an external circuit; and optionally patterning the transparent top electrode, to produce a finished electronic component, wherein the conductive polymer composition is preferably the conductive polymer composition presented herein. The presented method has the advantage of being solution-processable, which drastically reduces manufacturing costs in comparison to, e.g., physical vapor deposition methods for producing transparent electrodes.

[0016] The presented method is completely solution-processable, and thus a very cost- effective alternative for producing electronic components. The method may be carried out in ambient laboratory conditions. The need of expensive and complicated vacuum systems conventionally needed for top electrode deposition (e.g., ITO) is eliminated.

[0017] Use of a transparent conductive polymer film comprising poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a dopant in electronic components comprising quantum-confined nanocrystals is further provided.

[0018] Brief description of the drawings Figure 1 presents a transmittance spectrum of a conductive polymer film according to the invention,

[0019] Figure 2 schematically presents an electronic component according to the invention,

[0020] Figures 3a-d schematically present electronic components comprising a conductive polymer film according to the invention as a transparent top electrode,

[0021] Figure 4 schematically presents a patterning process of an electronic component according to the invention, and

[0022] Figure 5 schematically presents a patterning process of a top electrode on an electronic component according to the invention.

[0023] Detailed description

[0024] A conductive polymer composition is presented. The conductive polymer composition comprises poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), a dopant, and water. PEDOT:PSS is present in the composition typically in an amount of 0.1-10 wt-% of the total weight of the composition. The dopant is present typically in an amount of 0.01-20 wt-% of the total weight of the composition. Water is typically present in the composition in an amount of 70-99.9 wt-% of the total weight of the composition. The composition, in the form of an aqueous polymer solution, typically has a conductivity of 500 S / cm or more, such as 500-5000 S / cm.

[0025] The conductive polymer composition may be produced by providing an aqueous solution of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and mixing the solution with the dopant. Water may also be added in the polymer composition, either by first diluting the aqueous solution of PEDOT:PSS with water to a desired concentration, followed by addition of the dopant, or by first mixing the water with the dopant in a desired concentration, followed by mixing said water-dopant solution with the aqueous solution of PEDOT:PSS. The desired water concentration may be decided on, e.g., requirements for film deposition.

[0026] The dopant in the polymer composition increases the conductivity of the polymer composition compared to pristine PEDOT:PSS. Conductivity of undoped PEDOT:PSS is typically in the range of ca. 10-300 S / m. With the use of the dopant, the conductivity may thus be increased significantly, even up to several orders of magnitude. The increased conductivity facilitates the use of the polymer composition in electronics applications requiring high conductivity, such as photodetectors with quantum-confined nanocrystals as active layers. The dopant may be selected from the group comprising dopant is selected from the group comprising polar organic solvents, alcohols, salts, zwitterions, cosolvents, acids, amphiphilic fluorine- containing compounds, surfactants, and any combination thereof, preferably alcohols such as aliphatic alcohols, aromatic alcohols, compounds with two or more hydroxyl groups, more preferably ethylene glycol or phenol. In addition to the increased conductivity, the dopant decreases the surface tension of the polymer composition, thus facilitating better film morphology when producing films of the polymer composition.

[0027] A transparent conductive polymer film for electronic components comprising quantum-confined nanocrystals is provided. The polymer film comprises poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a dopant. The film has a sheet resistance of 500 Q / sq or less, such as 50-500 Q / sq. The polymer film has a transmittance of at least 50%, such as 50-100%, preferably 80-100%, at wavelengths from 170 to 2800 nm. Figure 1 presents a transmittance spectrum for a conductive polymer film. Transmittance of the film exceeds 80% over the entire measured range of 170-2500 nm.

[0028] Thickness of the conductive polymer film is typically in the range of 10-500 nm.

[0029] The dopant in the polymer film decreases the resistance of the polymer film compared to polymer films produced using pristine PEDOT:PSS. Polymer films produced using pristine PEDOT:PSS have sheet resistances typically ranging from 1 kQ / sq to even 100 kQ / sq, when measured by the four-point probe method. With the use of the dopant, the sheet resistance of the polymer films may thus be significantly decreased down to 500 Q / sq or less. The dopant may be selected from the group comprising polar organic solvents, alcohols, salts, zwitterions, cosolvents, acids, amphiphilic fluorine-containing compounds, surfactants, and any combination thereof, preferably alcohols such as aliphatic alcohols, aromatic alcohols, compounds with two or more hydroxyl groups, more preferably ethylene glycol or phenol. In addition to the increased conductivity, the dopant facilitates better film morphology in polymer films by decreasing the surface tension of the polymer composition used to produce said films. The polymer film may also comprise trace amounts of water and other elements or compounds due remains of the polymer composition and possible impurities therein.

[0030] An electronic component comprising quantum-confined nanocrystals is provided. A transparent top electrode of the electronic component may be produced using the conductive polymer composition as described herein. Alternatively, the electronic component may comprise the transparent conductive polymer film as provided herein as a transparent top electrode.

[0031] The electronic component may be a photodetector. More precisely, the photodetector may be an X-ray detector sensitive at the wavelength region of 5 pm to 10 nm. Alternatively or in addition, the photodetector may be a UV-visible light-near infrared (UV / VIS / NIR) photodetector sensitive at the wavelength region of 150-1100 nm. Alternatively or in addition, the photodetector may be a short-wave infrared (SWIR) detector sensitive at the wavelength region of 1100-2800 nm.

[0032] The photodetector may also be a multiple bandwidth photodetector. A multiple bandwidth photodetector has more than one sensitivity band selected from X-ray wavelength region of 5 pm to 10 nm, UV-visible light-near infrared (UV / VIS / NIR) wavelength region of 150-1100 nm, short-wave infrared (SWIR) wavelength region of 1100-2800 nm, and any combination thereof. Multiple bandwidth photodetectors have the advantage of covering a wider wavelength range with a single device, whereby the device can be used for multiple purposes.

[0033] The multiple bandwidth photodetector may be a dual bandwidth photodetector having a first sensitivity band at the X-ray wavelength region of 5 pm to 10 nm and a second sensitivity band at the UV-visible light-near infrared (UV / VIS / NIR) wavelength region of 150-1100 nm.

[0034] Alternatively, the multiple bandwidth photodetector may be a dual bandwidth photodetector having a first sensitivity band at the X-ray wavelength region of 5 pm to 10 nm, and a second sensitivity band at the SWIR wavelength region of 1100-2800 nm.

[0035] Alternatively, the multiple bandwidth photodetector may be a dual bandwidth photodetector having a first sensitivity band at the UV-visible light-near infrared (UV / VIS / NIR) wavelength region of 150-1100 nm, and a second sensitivity band at the short-wave infrared (SWIR) wavelength region of 1100-2800 nm.

[0036] Alternatively or in addition, the multiple bandwidth photodetector may be a trial bandwidth photodetector having a first sensitivity band at the X-ray wavelength region of 5 pm to 10 nm, a second sensitivity band at the UV-visible light-near infrared (UV / VIS / NIR) wavelength region of 150-1100 nm, and a third sensitivity band at the short-wave infrared (SWIR) wavelength region of 1100-2800 nm.

[0037] Reference is made to Figures 2 and 3a-d. The electronic component EC typically comprises a bottom contact BC, optionally a pixelated array of bottom contacts; an active layer AL comprising the quantum-confined nanocrystals; a charge transport layer CT ; and a transparent top electrode TE.

[0038] The electronic component is typically built on a solid substrate S.

[0039] The bottom contact BC is configured to transform a signal obtained from the active layer AL into a measurable quantity, such as electric current. The electronic component EC may also comprise a pixelated array of bottom contacts BC to provide a pixel response for digitalization. The bottom contact BC may be configured to create a digitalized image based on the information, i.e. , collected charges at each pixel. The bottom contact BC is typically a contact pad configured to collect charges generated at the active layer AL. The substrate S may be selected from, e.g., a thin film transistor (TFT) panel comprising amorphous silicon, conductive oxides such as indium gallium zinc oxide (IGZO) or polycrystalline silicon, or a complementary metal-oxide semiconductor (CMOS) wafer.

[0040] The quantum-confined nanocrystals are arranged in the active layer AL. The active layer AL is configured to generate a signal, e.g., photoresponse in which incoming photons generate charges within the active layer AL.

[0041] The charge transport layer CT is configured to enable charge transport. Typically, the charge transport layer CT is either an electron transport layer or a hole transport layer, allowing for the transport of one kind of charges only. Therefore, unidirectional charge transport is enabled. Optionally, the electronic component EC may comprise two charge transport layers, a first charge transport layer CT 1 located between the bottom contact and the active layer, and a second charge transport layer CT2 located between the active layer and the top electrode. The first transport CT1 layer is an electron transport layer and the second charge transport layer is a hole transport layer, or alternatively, the first charge transport layer CT1 is a hole transport layer and the second charge transport layer CT2 is an electron transport layer. The electronic component EC may comprise either the first charge transport layer CT1 , the second charge transport layer CT2, or both charge transport layers CT1 , CT2.

[0042] The electronic component EC typically comprises a transparent top electrode TE configured to transport electrons to an external circuit. The transparent top electrode TE is preferably produced using the conductive polymer composition presented herein. Alternatively or in addition, the transparent top electrode preferably comprises the transparent conductive polymer film presented herein. The polymer composition is solution-processable, making it an attracting candidate for use in electronics components. Solution processing methods are generally safer, simpler and more cost-effective methods compared to, e.g., epitaxial methods for producing the top electrode TE.

[0043] The transparent conductive polymer film presented herein may be configured to function as the charge transport layer CT, CT2 and the transparent top electrode TE in the electronic component. In other words, a single layer of the polymer composition may have a double function both as a charge transport layer CT, CT2 and as the top electrode TE. Thereby, an additional charge transport layer may be completely omitted from the device structure. The use of the polymer film as the charge transport layer CT, CT2 simplifies the device structure. In electronic components EC based on different layers stacked upon each other, interfaces between the individual layers open possible recombination and loss channels. The simplified device scheme comprises a smaller number of interfaces between individual layers within the device, and thus, the number of loss channels is reduced. Furthermore, utilizing the polymer film both as the charge transport layer CT, CT2 and the top electrode TE simplifies the production process of the device. With a smaller number of individual layers to be deposited on top of each other, the number of process steps is reduced, again reducing the costs and chemical usage, as well as improving production safety of the manufacturing process.

[0044] The electronic component may further comprise an encapsulation layer ENC configured to protect the electronic component from the environment, e.g., from ambient moisture. The encapsulation layer may comprise, e.g., parylene coating or silicon nitride coating.

[0045] A method for producing an electronic component is provided. The method comprises providing an unfinished electronic component; depositing a conductive polymer composition on the unfinished electronic component to provide a conductive polymer layer; patterning the unfinished electronic component; optionally depositing a transparent top electrode TE on the patterned unfinished electronic component to connect the component to an external circuit; and optionally patterning the transparent top electrode TE, to produce a finished electronic component, wherein the conductive polymer composition is preferably the conductive polymer composition presented herein.

[0046] The expression ‘an unfinished electronic component’ means an electronic component in its mid-process stage, comprising, e.g., the bottom contact BC, the active layer AL and possibly the charge transport layer CT, CT 1 , CT2, but not yet the top electrode.

[0047] The method for producing an electronic component comprises depositing a conductive polymer composition on the unfinished electronic component to provide a conductive polymer layer on the unfinished electronic component. Preferably, the conductive polymer composition is the conductive polymer composition presented herein. As described above, the conductive polymer composition is solution- processable, which enables easy and straightforward deposition. The advantage of the polymer composition lies in that it is in the form of an aqueous solution. Unlike polymer compositions based on many other organic solvents, a water-based solution does not damage the underlying active layer, e.g., a layer of quantum-confined nanocrystals. The polymer composition may safely be deposited on top of the unfinished electronic component without the risk of damaging the underlying layers or without having to compensate for damage in the underlying layers by making them thicker than intended for the final device.

[0048] The conductive polymer layer may be deposited by well-known solution-based thin film preparation methods, e.g., by spin-coating, screen printing, slot die coating, flexography, rotogravure, or inkjet printing. After the deposition of the layer of conductive polymer composition, the structure is patterned. As a result of the patterning process, a plurality of active areas of the electronic component is defined. The layered structure is removed from outside the plurality of active areas in the patterning process to expose bottom contacts configured to be connected with the top electrode and bottom contacts configured to an external circuit, e.g., to a PCB board. As a result, a pixelated response may be obtained from the electronic component EC.

[0049] Well-known lithographical methods, such as photolithography, wet acid etching, plasma etching, and / or reactive ion etching, may be utilized in the patterning process.

[0050] Patterning the unfinished electronic component is typically carried out by a photolithographic process. The patterning process is schematically illustrated in Figure 4. The patterning process comprises: i) depositing a photoresist layer PR; ii) exposing the photoresist layer PR to irradiation through a shadow mask to define a plurality of active areas of the electronic component; and iii) developing the photoresist layer PR by a developer chemical; iv) patterning the conductive polymer layer P; v) patterning the active layer AL and the optional first charge transport layer CT 1 ; and vi) stripping off the photoresist PR using a polar organic solvent.

[0051] Deposition of the photoresist layer PR in i) may be carried out by any conventional means, such as spin-coating. The photoresist layer may be selected from conventional photoresists, such as novolac-based or acrylic-based photoresists.

[0052] Exposure of the photoresist PR in ii) may be carried out by conventional irradiation sources, such as visible light or UV light. The irradiation wavelength may be selected according to the used photoresist. Photoresists are commonly divided into positive and negative photoresists. Positive photoresists will become soluble in the developer chemical upon the exposure process, whereas negative photoresists are soluble in the developer chemical before the exposure step and will become insoluble when exposed. A shadow mask is typically used to define the plurality of active areas of the electronic component. With positive photoresists, the shadow mask is positioned to expose only the outside of the plurality of active areas, whereas with negative photoresists, the shadow mask is positioned to expose only the plurality of active areas. Preferably, positive photoresists are used, and only the outside of the plurality of active areas will be exposed to irradiation.

[0053] Developing the photoresist PR in iii) may be carried out by applying a developer chemical. Conventional developer chemicals, such as aqueous alkali solutions of, for example, tetramethylammonium hydroxide, may be used. Use of the conductive polymer layer P as described herein beneath the photoresist layer has the advantage of protecting the underlying layers during the developing. Basic aqueous developers tend to diffuse through layers of conventional, pristine PEDOT:PSS during the developing step. As a result, the active layer of the electronic component is damaged during the developing. Extensive research has shown that using the doped PEDOT:PSS as described herein as the conductive polymer layer P prevents the developer from diffusing into the active layer and damaging the active layer of the electronic component. As a result of the developing, photoresist remains only in the plurality of active areas of the electronic component. The photoresist PR will be removed from the outside of the plurality of the active areas, re-exposing the conductive polymer layer P at these areas.

[0054] Patterning the conductive polymer layer P in iv) may be carried out by, e.g., reactive ion etching or plasma etching, preferably reactive ion etching using oxygen ions as the reactive species. The reactive ion etching selectively removes the conductive polymer layer P, i.e., the doped PEDOT:PSS layer, from outside of the plurality of active areas.

[0055] Patterning the active layer AL and the optional first charge transport layer CT 1 in v) is typically carried out using conventional etching methods, such as wet acid etching, plasma etching, reactive ion etching, or a combination thereof. Patterning the active layer AL and the optional first charge transport layer CT 1 removes the active layer AL and the optional first charge transport layer CT1 from the outside of the plurality of active areas of the electronic component EC, re-exposing the bottom contacts configured to be connected with the top electrode BCT and bottom contacts configured to be connected to an external circuit BCE.

[0056] Patterning the conductive polymer layer P in iv) and patterning the active layer AL and the optional first charge transport layer CT1 in v) may be combined into a single patterning step. For example, reactive ion etching using oxygen ions as the reactive species can be utilized for patterning all layers simultaneously or subsequently.

[0057] To finish the patterning process, the photoresist PR is stripped off in vi) using a polar organic solvent, preferably selected from the group comprising ethyl lactate, dimethyl sulfoxide (DMSO), propylene glycol methyl ether acetate (PGMEA), and any combination thereof. Extensive research has shown that the conductive polymer layer P as described herein, i.e., doped PEDOT:PSS, protects the underlying layers at the plurality of active areas of the electronic component EC from damage during the stripping process. The advantage of better protection of the underlying active layer during the developing has further effects in the stripping phase as well. Since the underlying active layer is not damaged when protected by the doped PEDOT:PSS, it can also better withstand the effects of the solvent used in the stripping.

[0058] The patterning process may further comprise removing the conductive polymer layer P after patterning, i.e., after stripping off the photoresist at vi). The conductive polymer layer P may be removed by, e.g., by dissolving with water or by reactive ion etching, to re-expose the underlying layers. For example in situations where the electronic component EC comprises a second charge transport layer CT2 that is different from the conductive polymer film, the conductive polymer layer P may be unnecessary, and may be removed after patterning. In case the transparent top electrode TE is deposited in a separate process (see below), two consecutive conductive polymer layers P on top of each other might lead to poor film morphology, poor conductivity, or a thickness too large for the desired purpose. The function of the conductive polymer layer P is in this case to act as a protective layer during the patterning process.

[0059] The patterned conductive polymer layer may function as the transparent top electrode TE of the electronic component.

[0060] Alternatively, the transparent top electrode TE may be deposited in a separate process by depositing a transparent top electrode TE on the patterned unfinished electronic component obtained in vi), followed by patterning the transparent top electrode TE.

[0061] Material of the transparent top electrode TE is selected from the group comprising conducting polymers, semi-transparent or transparent semiconductors, semi- transparent or transparent metal thin films, and any combination thereof, preferably conducting polymers such as PEDOT:PSS or semi-transparent semiconductors such as indium tin oxide (ITO). More preferably, the transparent top electrode TE is the transparent conductive polymer film presented herein.

[0062] The transparent top electrode TE may be deposited by any suitable means according to the selected electrode material. The transparent top electrode TE may be deposited by physical vapor deposition methods, such as e-beam evaporation, thermal evaporation, or sputtering, or by solution processes, such as spin-coating, screen printing, slot die coating, flexography, rotogravure, or inkjet printing. Preferably, the transparent top electrode TE is deposited by spin-coating.

[0063] The transparent top electrode TE may be patterned in a second patterning process to provide electrical contact between the top electrode and the bottom contact configured to be connected with the top electrode BCT. Reference is made to Figure 5. The electrode material needs to be removed from the bottom contacts configured to be connected to an external circuit BCE.

[0064] The second patterning process is typically carried out by repeating i) ... iv) and vi) of the patterning process, i.e., by ii-i) depositing a photoresist layer PR; ii-ii) exposing the photoresist layer PR to irradiation through a shadow mask to define a plurality of active areas of the electronic component; and ii-iii) developing the photoresist layer PR by a developer chemical; ii-iv) patterning the top electrode TE; and ii-vi) stripping off the photoresist PR using a polar organic solvent, in a similar manner as described above.

[0065] In ii-iv), the pattern is designed such that the top electrode TE will remain at the plurality of active areas and extend to the bottom contacts BCT configured to be connected to the top electrode TE, thus creating the connection between the top electrode and the bottom contacts BCT, and the top electrode TE is removed from outside of the plurality of active areas, thus enabling connecting the external circuit to the bottom contacts BCE configured to be connected to the external circuit.

[0066] Thus, solution-processable, low-resistance transparent top electrodes may be produced by using the method described herein. Examples

[0067] Example 1 : Photodetector

[0068] A silicon wafer with repeating active areas with CMOS circuitry was used as a substrate.

[0069] A first charge transport layer was deposited by spin-coating zinc oxide nanoparticle solution onto the substrate. The active layer of quantum-confined nanocrystals was deposited by spin-coating a nanocrystal ink onto the first charge transport layer. A conductive polymer composition of Example 1 was deposited on top of the active layer by spin-coating.

[0070] A layer of a novolac-based photoresist AZ1518 from Microchemicals GmbH was deposited on top of the conductive polymer layer by spin-coating. The photoresist layer was exposed to irradiation at 310-450 nm through a shadow mask to define a plurality of active areas of the device. The exposed photoresist layer was developed using an aqueous solution of TMAOH to remove any photoresist outside of the active areas.

[0071] The conductive polymer layer was removed from outside of the active areas using reactive ion etching with oxygen ions as the reactive species. The active layer and the first charge transport layer were removed from outside of the active areas by wet acid etching using an aqueous solution of HNO3 (1 :3 HNCh^O, vokvol) for 1 minute at ambient temperature. The photoresist was stripped off by rinsing with ethyl lactate.

[0072] A second layer of the conductive polymer composition was deposited on top of the patterned structure.

[0073] The photoresist deposition, the exposure, the developing, and the reactive ion etching steps were repeated to pattern the second conductive polymer layer. Finally, the photoresist was stripped off by rinsing with a polar solvent to produce a transparent top electrode of doped PEDOT:PSS.

Claims

Claims1 . A conductive polymer composition, comprising poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), in an amount of 0.1-10 wt-% of the total weight of the composition; a dopant, in an amount of 0.01-20 wt-% of the total weight of the composition; and- water, in an amount of 70-99.9 wt-% of the total weight of the composition, wherein the composition has a conductivity of 500 S / cm or more, such as 500-5000 S / cm.

2. The conductive polymer composition of claim 1 , wherein the dopant is selected from the group comprising polar organic solvents, alcohols, , salts, zwitterions, cosolvents, acids, amphiphilic fluorine-containing compounds, surfactants, and any combination thereof, preferably alcohols such as aliphatic alcohols, aromatic alcohols, compounds with two or more hydroxyl groups.

3. A method for producing the conductive polymer composition of claim 1 , the method comprising providing an aqueous solution of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS); and mixing the aqueous solution of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with a dopant.

4. The method of claim 3, wherein the dopant is selected from the group comprising polar organic solvents, alcohols, organosulphur compounds such as dimethyl sulfoxide, salts, zwitterions, cosolvents, acids, amphiphilic fluorine-containing compounds, surfactants, and any combination thereof, preferably alcohols such as ethylene glycol, phenol, and / or geminal diols.

5. A transparent conductive polymer film for electronic components comprising quantum-confined nanocrystals, wherein the film comprises poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a dopant, wherein the film has a sheet resistance of 500 Q / sq or less, such as 50-500Q / sq, and wherein the film has a transmittance of at least 50%, such as 50- 100%, preferably 80-100%, at wavelengths from 170 to 2800 nm.

6. The transparent conductive polymer film of claim 5, wherein the dopant is selected from the group comprising polar organic solvents, alcohols, salts, zwitterions, cosolvents, acids, amphiphilic fluorine-containing compounds, surfactants, and any combination thereof, preferably alcohols such as aliphatic alcohols, aromatic alcohols, compounds with two or more hydroxyl groups.

7. An electronic component (EC) comprising quantum-confined nanocrystals, a transparent top electrode of which is produced using the conductive polymer composition of claim 1 or 2, or wherein the electronic component (EC) comprises the transparent conductive polymer film of claim 5 or 6 as a transparent top electrode (TE).

8. The electronic component (EC) of claim 7, wherein the electronic component is a photodetector.

9. The electronic component (EC) of claim 8, wherein the photodetector is an X-ray detector sensitive at the wavelength region of 5 pm to 10 nm.

10. The electronic component (EC) of claim 8, wherein the photodetector is a UV-visible light-near infrared (UV / VIS / NIR) photodetector sensitive at the wavelength region of 150-1100 nm.

11. The electronic component (EC) of claim 8, wherein the photodetector is a short-wave infrared (SWIR) detector sensitive at the wavelength region of 1100-2800 nm.

12. The electronic component (EC) of any of claims 8 to 11 , wherein the photodetector is a multiple bandwidth photodetector having more than one sensitivity band selected from X-ray wavelength region of 5 pm to 10 nm, UV / VIS / NIR wavelength region of 150-1100 nm, short-wave infrared (SWIR) wavelength region of 1100-2800 nm, and any combination thereof.

13. The multiple bandwidth photodetector of claim 12, wherein the photodetector is a dual bandwidth photodetector having a first sensitivity band at the X-ray wavelength region of 5 pm to 10 nm and a second sensitivity band at the UV / VIS / NIR wavelength region of 150-1100 nm.

14. The multiple bandwidth photodetector of claim 12, wherein the photodetector is a dual bandwidth photodetector having a first sensitivity band at the X-ray wavelength region of 5 pm to 10 nm, and a second sensitivity band at the SWIR wavelength region of 1100-2800 nm.

15. The electronic component (EC) of any of claims 7 to 14, wherein the electronic component comprises a bottom contact (BC), optionally a pixelated array of bottom contacts; an active layer (AL) comprising the quantum-confined nanocrystals; a charge transport layer (CT, CT1, CT2); and a transparent top electrode (TE), preferably wherein the transparent top electrode (TE) is produced using the conductive polymer composition of claim 1 , or the transparent top electrode is the transparent conductive polymer film of claim 5 or 6.

16. The electronic component (EC) of claim 15, wherein the transparent conductive polymer film of claim 5 is configured to function as the charge transport layer (CT, CT2) and the transparent top electrode (TE).

17. A method for producing the electronic component of any of claims 7 to 16, the method comprising providing an unfinished electronic component; depositing a conductive polymer composition on the unfinished electronic component to provide a conductive polymer layer; patterning the unfinished electronic component; optionally depositing a transparent top electrode on the patterned unfinished electronic component to connect the component to an external circuit; and optionally patterning the transparent top electrode, to produce a finished electronic component, wherein the conductive polymer composition is preferably a conductive polymer composition according to claim 1 or 2.

18. The method of claim 17, wherein the conductive polymer layer is deposited by spin-coating, screen printing, slot die coating, flexography, rotogravure, or inkjet printing.

19. The method of claim 17 or 18, wherein the patterning is performed by wet acid etching, plasma etching, or reactive ion etching.

20. The method of any of claims 17 to 19, further comprising removing the conductive polymer layer after patterning, e.g., by dissolving with water.

21. The method of any of claims 17 to 20, wherein the transparent top electrode (TE) is selected from the group comprising conducting polymers, semitransparent or transparent semiconductors, semi-transparent or transparent metal thin films, and any combination thereof, preferably conducting polymers such as PEDOT:PSS or semi-transparent semiconductors such as indium tin oxide (ITO).

22. Use of a transparent conductive polymer film comprising poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a dopant in electronic components comprising quantum-confined nanocrystals.

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