Because poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)is water processable,thermally stable,and highly conductive,PEDOT:PSS and its composites have been considered to be one of the most promising f...Because poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)is water processable,thermally stable,and highly conductive,PEDOT:PSS and its composites have been considered to be one of the most promising flexible thermoelectric materials.However,the PEDOT:PSS film prepared from its commercial aqueous dispersion usually has very low conductivity,thus cannot be directly utilized for TE applications.Here,a simple environmental friendly strategy via femtosecond laser irradiation without any chemical dopants and treatments was demonstrated.Under optimal conditions,the electrical conductivity of the treated film is increased to 803.1 S cm^(-1)from 1.2 S cm^(-1)around three order of magnitude higher,and the power factor is improved to 19.0μW m^(-1)K^(-2),which is enhanced more than 200 times.The mechanism for such remarkable enhancement was attributed to the transition of the PEDOT chains from a coil to a linear or expanded coil conformation,reduction of the interplanar stacking distance,and the removal of insulating PSS with increasing the oxidation level of PEDOT,facilitating the charge transportation.This work presents an effective route for fabricating high-performance flexible conductive polymer films and wearable thermoelectric devices.展开更多
Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT...Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT/PSS was dissolved in chloroform and spread on subphase containing 0.04wt% FeCl_3.Conductive Y-type mixed LB films was successfully prepared under the condition of surface pressure with 30 mN/m,pH 3.8,and 19℃.UV-VIS spectrum showed that well ordered layer-by-layer fabrication of mixed films were obtained and thickness of single layer film with about 5 nm was evaluated.The morphology image of mixed LB film was observed by atomic force microscopy (AFM).The conductivity of mixed LB film was about 1.8×10^(-5)S/cm and the film showed sensitivity to NH_3 at the same time.展开更多
Recently, a high-performance and low-priced transparent conductive film has been expected to be developed because flexible devices produced using organic materials have been actively studied. An indium tin oxide (ITO)...Recently, a high-performance and low-priced transparent conductive film has been expected to be developed because flexible devices produced using organic materials have been actively studied. An indium tin oxide (ITO) thin film, which has been generally used as a material for a transparent conductive film, has problems, such as fragility to bending stress and depletion of the resource. The present study used poly(3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), an organic electroconductive material, and examined the improvement in the resistance value and visible light transmittance of a transparent conductive film produced using the ink-jet method. In previous studies, we reported that, to improve the resistance value and visible light transmittance of a thin film, it was effective to clean the film substrate with ultraviolet/ozone (UV/O<sub>3</sub>) treatment, anneal the film after it was deposited on the substance, and dip the annealed film into a polar solvent. Focusing on the thin film processing between printing operations, the present study improved resistance value and visible light transmittance by examining both the application methods of a polar solvent and the annealing time between printing operations. As a result, the resistance value and visible light transmittance of a PEDOT:PSS thin film were 390.4 Ω and 86.6%, respectively. This film was obtained by applying a polar solvent and performing annealing for 30 min between printing operations. The printing was performed three times.展开更多
An increase of work function （0.3 eV） is achieved by irradiating poly（3,4-ethylenedioxythiophene）：poly（styrene sul- fonate） （PEDOT：PSS） film in vacuum with 254-nm ultraviolet （UV） light. The mechanism for ...An increase of work function （0.3 eV） is achieved by irradiating poly（3,4-ethylenedioxythiophene）：poly（styrene sul- fonate） （PEDOT：PSS） film in vacuum with 254-nm ultraviolet （UV） light. The mechanism for such an improvement is investigated by photoelectron yield spectroscopy, X-ray photo electron energy spectrum, and field emission technique. Sur- face oxidation and composition change are found as the reasons for work function increase. The UV-treated PEDOT：PSS film is used as the hole injection layer in a hole-only device. Hole injection is improved by UV-treated PEDOT：PSS film without baring the enlargement of film resistance. Our result demonstrates that UV treatment is more suitable for modifying the injection barrier than UV ozone exposure.展开更多
Flexible devices manufactured using printed electronics have attracted the attention of many researchers. A high-performance transparent conductive film exhibiting high flexibility and elasticity is expected to be dev...Flexible devices manufactured using printed electronics have attracted the attention of many researchers. A high-performance transparent conductive film exhibiting high flexibility and elasticity is expected to be developed because of its need for the creation of flexible devices. An indium tin oxide (ITO) thin film, which has generally been used, has weaknesses such as fragility to bending stress and depletion of the resource. This study focused on poly (3, 4-ethy-lenedioxythiophene)/poly (styrenesulfonate) (PEDOT:PSS), a conductive polymer material, and examined improvement in the resistivity and transmittance of the transparent conductive film produced using an inkjet method. The present study improved the electrical and optical characteristics of the thin film by examining the annealing temperature between printing operations and the application method of a polar solvent. As a result, the resistivity and transmittance of a PEDOT:PSS thin film were 1.49 × 10-3 Ω·cm and 89.2%, respectively. This film was obtained by annealing at 90°C for 30 min and applying a polar solvent, using an inkjet printer, between printing operations. The printing was performed three times.展开更多
Flexible devices produced using organic materials have attracted the attention of many researchers. Important components of these flexible devices include transparent electrodes, which transmit visible light and posse...Flexible devices produced using organic materials have attracted the attention of many researchers. Important components of these flexible devices include transparent electrodes, which transmit visible light and possess conductivity. The present study improved the characteristics of a transparent conductive film that was made of poly(3, 4 ethylenedioxythiophene):poly(styrenesul-fonate) (PEDOT:PSS), an organic conductive material, and that had been prepared using ink-jet printing. To improve the resistance value and visible light transmittance of the film, the film substrate was first cleaned with ultraviolet/ozone treatment, and then the film was annealed after it was deposited on the substrate and dipped into a polar solvent. Consequently, the resistance value of the thin film decreased. However, the surface state of the film changed according to the treatment method and affected its visible light transmittance. Thus, the surface state of the film substrate, the annealing temperature after film deposition, and the dipping treatment with a polar solvent influenced the characteristics of a thin film.展开更多
Flexible thermoelectrics provide a distinct solution for developing sustainable and portable power supplies.Inorganic/organic material compositing is an effective strategy to induce a significant enhancement of thermo...Flexible thermoelectrics provide a distinct solution for developing sustainable and portable power supplies.Inorganic/organic material compositing is an effective strategy to induce a significant enhancement of thermoelectric(TE)performance.However,the poor electrical performance of inorganic/organic material is attributed to the poor carrier transport between organic/inorganic interfaces induced by the low contribution of composited inorganic materials.Herein,we prepared a high room temperature figure-of-merit(ZT)value of~0.19 and high bending resistance(surviving 1200 bending cycles at the bending radius of 16.5 mm)of p-type poly(3,4-ethylenedioxy thiophene):poly(4-styrenesulfonate)(PEDOT:PSS)/Bi_(0.5)Sb_(1.5)Te_(3)free-standing composite film via a facile vacuum-as sis ted filtration approach.Compositing Bi_(0.5)Sb_(1.5)Te_(3)nano-spherical particles into PEDOT:PSS results in the optimized interfacial contact and carrier concentration,leading to a high Seebeck coefficient of~43.79μV·K^(-1).Accordingly,a high-power factor of~1.52μW·cm^(-1)·K^(-2)is achieved in the PEDOT:PSS/Bi_(0.5)Sb_(1.5)Te_(3)composite film at room temperature.In addition,the PEDOT:PSS/Bi_(0.5)Sb_(1.5)Te_(3)interfaces with phase boundaries,nanograins and point defects could further decrease the thermal conductivity to~0.20 W·m^(-1)K^(-1),leading to a high ZT value.Furthermore,a 6-leg freestanding film device was assembled,which provided an output power of 44.94 nW.This study demonstrates that free-standing organic/inorganic composite films are effective power sources for wearable electronic products.展开更多
Degradation and delamination resulting from environmental humidity have been technically challenging for poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)thin-film processing.To overcome this problem...Degradation and delamination resulting from environmental humidity have been technically challenging for poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)thin-film processing.To overcome this problem,we introduced a one-step photolithographic method to both pattern and link a PEDOT:PSS film onto a poly(ethylene glycol)(PEG)layer as a hybrid thin film structure on a flexible substrate.This film exhibited excellent long-term moisture stability(more than 10 days)and lithographic resolution(as low as 2μm).Mechanical characterizations were performed,including both stretching and bending tests,which illustrated the strong adhesion present between the PEDOT:PSS and PEG layers as well as between the hybrid thin film and substrate.Moreover,the hybrid moisture-absorbable film showed a quick response of its permittivity to environmental humidity variations,in which the patterned PEDOT:PSS layer served as an electrode and the PEG layer as a moisture-sensing element.Perspiration tracking over various parts of the body surface as well as breath rate measurement under the nose were successfully carried out as demonstrations,which illustrated the potential utility of this stable hybrid thin film for emerging flexible and wearable electronic applications.展开更多
A Langmuir-Blodgett （LB） inducing method was firstly used to prepare single layer and multilayer conducting composite PEDOT-PSS film. The film-forming ability of ionization ODA and ODA-SA monolayer spread on PEDOT-P...A Langmuir-Blodgett （LB） inducing method was firstly used to prepare single layer and multilayer conducting composite PEDOT-PSS film. The film-forming ability of ionization ODA and ODA-SA monolayer spread on PEDOT-PSS nanoparticle sub-phase and the behavior of ODA/PEDOT-PSS assembly particles on pure water were firstly investigated. The results indicated that nanoparticles in the suphase are packed in the ionization monolayer and stable complex Langmuir film is formed at the air/water interface. It has been found that the best film-forming conditions for composite film are as follows：distinct interface was formed between ODA and PEDOT-PSS layer and single layer thickness of PEDOT-PSS was about 23 nm,well accordant to the size of PEDOT-PSS nanoparticles. Different structures were designed to test the conductive ability of these composite films and a variable range hopping （VRH） model was used to explain the film conductive mechanism. The results indicated that a 3D-VRH model explained well the transferring of charge carrier in the multilayer film.展开更多
Selectivity improvement of gas sensor based on Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin film to ammonia gas has been studied. The PEDOT:PSS thin films were deposited on glass and FR4 su...Selectivity improvement of gas sensor based on Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin film to ammonia gas has been studied. The PEDOT:PSS thin films were deposited on glass and FR4 substrates by using a spin-coating technique. PEDOT:PSS solution was spread on the substrate followed by spinning at fixed rate. Then, the imprinting process of gas sensor was performed by injecting ammonia gas into the spin-coating chamber. Finally, the gas sensor was dried on a controllable hot plate. Current-voltage characteristics of the films were measured by using calibrated electrometer. The results show that by imprinting of ammonia gas to the film affects the electrical conductivity of the film. It is also shown that the electron transport in the PEDOT:PSS thin film tends to be ohmic-contact. When the imprinted sensor is exposed in ammonia gas, we obtained that the sensor has short response and recovery time, a good repeatability (reversible), and higher sensitivity to ammonia gas. To this end, we found that ammonia imprinting on the surface of PEDOT:PSS thin film can improve the selectivity of the sensor to ammonia gas. It indicates that our method can be used for fabricating the sensor which has a single selectivity.展开更多
基金supported by the National Key Research and Development Program of China(2020YFA0715000)the Guangdong Basic and Applied Basic Research Foundation(2020A1515110250,2021B1515120041)+1 种基金the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHT2020-005)the Fundamental Research Funds for the Central Universities(2020IVA068,2021lll007JC)
文摘Because poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)is water processable,thermally stable,and highly conductive,PEDOT:PSS and its composites have been considered to be one of the most promising flexible thermoelectric materials.However,the PEDOT:PSS film prepared from its commercial aqueous dispersion usually has very low conductivity,thus cannot be directly utilized for TE applications.Here,a simple environmental friendly strategy via femtosecond laser irradiation without any chemical dopants and treatments was demonstrated.Under optimal conditions,the electrical conductivity of the treated film is increased to 803.1 S cm^(-1)from 1.2 S cm^(-1)around three order of magnitude higher,and the power factor is improved to 19.0μW m^(-1)K^(-2),which is enhanced more than 200 times.The mechanism for such remarkable enhancement was attributed to the transition of the PEDOT chains from a coil to a linear or expanded coil conformation,reduction of the interplanar stacking distance,and the removal of insulating PSS with increasing the oxidation level of PEDOT,facilitating the charge transportation.This work presents an effective route for fabricating high-performance flexible conductive polymer films and wearable thermoelectric devices.
文摘Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT/PSS was dissolved in chloroform and spread on subphase containing 0.04wt% FeCl_3.Conductive Y-type mixed LB films was successfully prepared under the condition of surface pressure with 30 mN/m,pH 3.8,and 19℃.UV-VIS spectrum showed that well ordered layer-by-layer fabrication of mixed films were obtained and thickness of single layer film with about 5 nm was evaluated.The morphology image of mixed LB film was observed by atomic force microscopy (AFM).The conductivity of mixed LB film was about 1.8×10^(-5)S/cm and the film showed sensitivity to NH_3 at the same time.
文摘Recently, a high-performance and low-priced transparent conductive film has been expected to be developed because flexible devices produced using organic materials have been actively studied. An indium tin oxide (ITO) thin film, which has been generally used as a material for a transparent conductive film, has problems, such as fragility to bending stress and depletion of the resource. The present study used poly(3, 4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), an organic electroconductive material, and examined the improvement in the resistance value and visible light transmittance of a transparent conductive film produced using the ink-jet method. In previous studies, we reported that, to improve the resistance value and visible light transmittance of a thin film, it was effective to clean the film substrate with ultraviolet/ozone (UV/O<sub>3</sub>) treatment, anneal the film after it was deposited on the substance, and dip the annealed film into a polar solvent. Focusing on the thin film processing between printing operations, the present study improved resistance value and visible light transmittance by examining both the application methods of a polar solvent and the annealing time between printing operations. As a result, the resistance value and visible light transmittance of a PEDOT:PSS thin film were 390.4 Ω and 86.6%, respectively. This film was obtained by applying a polar solvent and performing annealing for 30 min between printing operations. The printing was performed three times.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61076057,61376059,61171023,and 91221202,)the National Basic Research Program of China(Grant Nos.2012CB932701 and 2011CB933001)
文摘An increase of work function （0.3 eV） is achieved by irradiating poly（3,4-ethylenedioxythiophene）：poly（styrene sul- fonate） （PEDOT：PSS） film in vacuum with 254-nm ultraviolet （UV） light. The mechanism for such an improvement is investigated by photoelectron yield spectroscopy, X-ray photo electron energy spectrum, and field emission technique. Sur- face oxidation and composition change are found as the reasons for work function increase. The UV-treated PEDOT：PSS film is used as the hole injection layer in a hole-only device. Hole injection is improved by UV-treated PEDOT：PSS film without baring the enlargement of film resistance. Our result demonstrates that UV treatment is more suitable for modifying the injection barrier than UV ozone exposure.
文摘Flexible devices manufactured using printed electronics have attracted the attention of many researchers. A high-performance transparent conductive film exhibiting high flexibility and elasticity is expected to be developed because of its need for the creation of flexible devices. An indium tin oxide (ITO) thin film, which has generally been used, has weaknesses such as fragility to bending stress and depletion of the resource. This study focused on poly (3, 4-ethy-lenedioxythiophene)/poly (styrenesulfonate) (PEDOT:PSS), a conductive polymer material, and examined improvement in the resistivity and transmittance of the transparent conductive film produced using an inkjet method. The present study improved the electrical and optical characteristics of the thin film by examining the annealing temperature between printing operations and the application method of a polar solvent. As a result, the resistivity and transmittance of a PEDOT:PSS thin film were 1.49 × 10-3 Ω·cm and 89.2%, respectively. This film was obtained by annealing at 90°C for 30 min and applying a polar solvent, using an inkjet printer, between printing operations. The printing was performed three times.
文摘Flexible devices produced using organic materials have attracted the attention of many researchers. Important components of these flexible devices include transparent electrodes, which transmit visible light and possess conductivity. The present study improved the characteristics of a transparent conductive film that was made of poly(3, 4 ethylenedioxythiophene):poly(styrenesul-fonate) (PEDOT:PSS), an organic conductive material, and that had been prepared using ink-jet printing. To improve the resistance value and visible light transmittance of the film, the film substrate was first cleaned with ultraviolet/ozone treatment, and then the film was annealed after it was deposited on the substrate and dipped into a polar solvent. Consequently, the resistance value of the thin film decreased. However, the surface state of the film changed according to the treatment method and affected its visible light transmittance. Thus, the surface state of the film substrate, the annealing temperature after film deposition, and the dipping treatment with a polar solvent influenced the characteristics of a thin film.
基金financially supported by the National Natural Science Foundation of China(Nos.12204355 and 52272210)the Natural Science Foundations of Shandong Province(Nos.ZR2023ME001 and ZR2022QA018)+1 种基金China Postdoctoral Science Foundation(No.2023M732609)the Doctoral Research Initiation Fund of Weifang University(Nos.2023BS01 and 2023BS06)。
文摘Flexible thermoelectrics provide a distinct solution for developing sustainable and portable power supplies.Inorganic/organic material compositing is an effective strategy to induce a significant enhancement of thermoelectric(TE)performance.However,the poor electrical performance of inorganic/organic material is attributed to the poor carrier transport between organic/inorganic interfaces induced by the low contribution of composited inorganic materials.Herein,we prepared a high room temperature figure-of-merit(ZT)value of~0.19 and high bending resistance(surviving 1200 bending cycles at the bending radius of 16.5 mm)of p-type poly(3,4-ethylenedioxy thiophene):poly(4-styrenesulfonate)(PEDOT:PSS)/Bi_(0.5)Sb_(1.5)Te_(3)free-standing composite film via a facile vacuum-as sis ted filtration approach.Compositing Bi_(0.5)Sb_(1.5)Te_(3)nano-spherical particles into PEDOT:PSS results in the optimized interfacial contact and carrier concentration,leading to a high Seebeck coefficient of~43.79μV·K^(-1).Accordingly,a high-power factor of~1.52μW·cm^(-1)·K^(-2)is achieved in the PEDOT:PSS/Bi_(0.5)Sb_(1.5)Te_(3)composite film at room temperature.In addition,the PEDOT:PSS/Bi_(0.5)Sb_(1.5)Te_(3)interfaces with phase boundaries,nanograins and point defects could further decrease the thermal conductivity to~0.20 W·m^(-1)K^(-1),leading to a high ZT value.Furthermore,a 6-leg freestanding film device was assembled,which provided an output power of 44.94 nW.This study demonstrates that free-standing organic/inorganic composite films are effective power sources for wearable electronic products.
基金This work was supported in part by the NSF Award(ECCS-1307831)NIH Award(1R21CA173243-01A1)to TP.RL acknowledges the fellowship support from the China Scholarship Council(CSC).
文摘Degradation and delamination resulting from environmental humidity have been technically challenging for poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)thin-film processing.To overcome this problem,we introduced a one-step photolithographic method to both pattern and link a PEDOT:PSS film onto a poly(ethylene glycol)(PEG)layer as a hybrid thin film structure on a flexible substrate.This film exhibited excellent long-term moisture stability(more than 10 days)and lithographic resolution(as low as 2μm).Mechanical characterizations were performed,including both stretching and bending tests,which illustrated the strong adhesion present between the PEDOT:PSS and PEG layers as well as between the hybrid thin film and substrate.Moreover,the hybrid moisture-absorbable film showed a quick response of its permittivity to environmental humidity variations,in which the patterned PEDOT:PSS layer served as an electrode and the PEG layer as a moisture-sensing element.Perspiration tracking over various parts of the body surface as well as breath rate measurement under the nose were successfully carried out as demonstrations,which illustrated the potential utility of this stable hybrid thin film for emerging flexible and wearable electronic applications.
基金Supported by the National Natural Science Foundation of China (No. 60372002)
文摘A Langmuir-Blodgett （LB） inducing method was firstly used to prepare single layer and multilayer conducting composite PEDOT-PSS film. The film-forming ability of ionization ODA and ODA-SA monolayer spread on PEDOT-PSS nanoparticle sub-phase and the behavior of ODA/PEDOT-PSS assembly particles on pure water were firstly investigated. The results indicated that nanoparticles in the suphase are packed in the ionization monolayer and stable complex Langmuir film is formed at the air/water interface. It has been found that the best film-forming conditions for composite film are as follows：distinct interface was formed between ODA and PEDOT-PSS layer and single layer thickness of PEDOT-PSS was about 23 nm,well accordant to the size of PEDOT-PSS nanoparticles. Different structures were designed to test the conductive ability of these composite films and a variable range hopping （VRH） model was used to explain the film conductive mechanism. The results indicated that a 3D-VRH model explained well the transferring of charge carrier in the multilayer film.
文摘Selectivity improvement of gas sensor based on Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin film to ammonia gas has been studied. The PEDOT:PSS thin films were deposited on glass and FR4 substrates by using a spin-coating technique. PEDOT:PSS solution was spread on the substrate followed by spinning at fixed rate. Then, the imprinting process of gas sensor was performed by injecting ammonia gas into the spin-coating chamber. Finally, the gas sensor was dried on a controllable hot plate. Current-voltage characteristics of the films were measured by using calibrated electrometer. The results show that by imprinting of ammonia gas to the film affects the electrical conductivity of the film. It is also shown that the electron transport in the PEDOT:PSS thin film tends to be ohmic-contact. When the imprinted sensor is exposed in ammonia gas, we obtained that the sensor has short response and recovery time, a good repeatability (reversible), and higher sensitivity to ammonia gas. To this end, we found that ammonia imprinting on the surface of PEDOT:PSS thin film can improve the selectivity of the sensor to ammonia gas. It indicates that our method can be used for fabricating the sensor which has a single selectivity.
