We report for the first time highly conductive poly（3,4-ethylenedioxythiophene）： poly（4-styrenesulfonate） （PEDOT：PSS）/graphene composites fabricated by in situ polymerization and their applications in a thermo...We report for the first time highly conductive poly（3,4-ethylenedioxythiophene）： poly（4-styrenesulfonate） （PEDOT：PSS）/graphene composites fabricated by in situ polymerization and their applications in a thermoelectric device and a platinum （Pt）-free dye-sensitized solar cell （DSSC） as energy harvesting systems. Graphene was dispersed in a solution of poly（4-styrenesulfonate） （PSS） and polymerization was directly carried out by addition of 3,4-ethylenedioxythiophene （EDOT） monomer to the dispersion. The content of the graphene was varied and optimized to give the highest electrical conductivity. The composite solution was ready to use without any reduction process because reduced graphene oxide was used. The fabricated film had a conductivity of 637 S.cm-1, corresponding to an enhancement of 41%, after the introduction of 3 wt.% graphene without any further complicated reduction processes of graphene being required. The highly conductive composite films were employed in an organic thermoelectric device, and the device showed a power factor of 45.7 μW·m^-1K^-2 which is 93% higher than a device based on pristine PEDOT：PSS. In addition, the highly conductive composite films were used in Pt-free DSSCs, showing an energy conversion efficiency of 5.4%, which is 21% higher than that of a DSSC based on PEDOT：PSS.展开更多
Metal halide perovskite solar cells(PSCs)have attracted tremendous attention as an emerging photovoltaic technology due to their high efficiency,low cost and ease of fabrication from earth-abundant materials[1,2].The ...Metal halide perovskite solar cells(PSCs)have attracted tremendous attention as an emerging photovoltaic technology due to their high efficiency,low cost and ease of fabrication from earth-abundant materials[1,2].The power conversion efficiencies(PCEs)have been rapidly boosted from 3.8%in the pioneer’s work to a certified 24.2%nowadays in just ten years[3].The PCE breakthroughs in PSCs have mostly adopted full lead-based perovskites(APbX3)with bandgaps of 1.5–1.6 eV.展开更多
As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells(PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide(GO)-modified PEDO...As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells(PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide(GO)-modified PEDOT:PSS hole transport layer was fabricated by spin-coating a GO solution onto the PEDOT:PSS surface. PSCs fabricated on a GO-modified PEDOT:PSS layer exhibited a power conversion efficiency(PCE) of 15.34%, which is higher than 11.90% of PSCs with the PEDOT:PSS layer.Furthermore, the stability of the PSCs was significantly improved, with the PCE remaining at 83.5% of the initial PCE values after aging for 39 days in air. The hygroscopic PSS material at the PEDOT:PSS surface was partlyremoved during spin-coating with the GO solution, which improves the moisture resistance and decreases the contact barrier between the hole transport layer and perovskite layer. The scattered distribution of the GO at the PEDOT:PSS surface exhibits superior wettability, which helps to form a high-quality perovskite layer with better crystallinity and fewer pin holes. Furthermore, the hole extraction selectivity of the GO further inhibits the carrier recombination at the interface between the perovskite and PEDOT:PSS layers. Therefore, the cooperative interactions of these factors greatly improve the light absorption of the perovskite layer, the carrier transport and collection abilities of the PSCs, and especially the stability of the cells.展开更多
Graphene sheets(GNs) have high conductivity, but they exhibit weak electromagnetic(EM) wave absorption performance. Here, poly(3,4-ethylenedioxythiophene)(PEDOT) nanofibers were decorated on the surface of GNs in whic...Graphene sheets(GNs) have high conductivity, but they exhibit weak electromagnetic(EM) wave absorption performance. Here, poly(3,4-ethylenedioxythiophene)(PEDOT) nanofibers were decorated on the surface of GNs in which the residual defects and groups act as the active sites and therefore are beneficial for the deposition of PEDOT nanofibers.The SEM images display that PEDOT nanofibers are successfully decorated on the surface of GNs through in situ polymerization. The diameter of the PEDOT nanofibers were ranged from 15 to 50 nm with hundreds of nanometers in length. The EM wave absorption properties of graphene, PEDOT, and GNs-PEDOT were also investigated. Compared to pure graphene and PEDOT, the EM wave absorption properties of GNs-PEDOT improved significantly. The maximum value of RLwas up to-48.1 d B at 10.5 GHz with a thickness of only 2 mm. Meanwhile, the absorption bandwidth of RL values below-10 d B was 9.4 GHz(5.8–12.3, 12.9–15.8 GHz) in the thickness of 1.5–3 mm. The enhancement is attributed to the modification of PEDOT and the unique structure of nanofibers. On one hand, the deposition of PEDOT nanofibers on the surface of GNs decreases the conductivity of graphene, and makes impedance match better. On the other hand, the unique structure of PEDOT nanofibers results in relatively large specific surfaces areas, providing more active sites for reflection and scattering of EM waves. Therefore, our findings demonstrate that the deposition of conducting polymers on GNs by non-covalent bond is an efficient way to fabricate strong EM wave absorbers.展开更多
The easy oxidation and surface roughness of Cu nanowire （NW） films are the main bottlenecks for their usage in transparent conductive electrodes （TCEs）. Herein, we have developed a facile and scaled-up solution ro...The easy oxidation and surface roughness of Cu nanowire （NW） films are the main bottlenecks for their usage in transparent conductive electrodes （TCEs）. Herein, we have developed a facile and scaled-up solution route to prepare Cu NW-based TCEs by embedding Cu NWs into pre-coated smooth poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS） films on poly（ethylene terephthalate） （PET） substrates. The so obtained Cu NW- PEDOT：PSS/PET films have low surface roughness （-70 nm in height）, high stability toward oxidation and good flexibility. The optimal TCEs show a typical sheet resistance of 15Ω·sq-1 at high transparency （76% at A = 550 nm） and have been used successfully to make polymer （poly（3-hexylthiophene）：phenyl-C61- butyric acid methyl ester） solar cells, giving an efficiency of 1.4%. The overall properties of Cu NW-PEDOT：PSS/PET films demonstrate their potential application as a replacement for indium tin oxide in flexible solar cells.展开更多
文摘We report for the first time highly conductive poly（3,4-ethylenedioxythiophene）： poly（4-styrenesulfonate） （PEDOT：PSS）/graphene composites fabricated by in situ polymerization and their applications in a thermoelectric device and a platinum （Pt）-free dye-sensitized solar cell （DSSC） as energy harvesting systems. Graphene was dispersed in a solution of poly（4-styrenesulfonate） （PSS） and polymerization was directly carried out by addition of 3,4-ethylenedioxythiophene （EDOT） monomer to the dispersion. The content of the graphene was varied and optimized to give the highest electrical conductivity. The composite solution was ready to use without any reduction process because reduced graphene oxide was used. The fabricated film had a conductivity of 637 S.cm-1, corresponding to an enhancement of 41%, after the introduction of 3 wt.% graphene without any further complicated reduction processes of graphene being required. The highly conductive composite films were employed in an organic thermoelectric device, and the device showed a power factor of 45.7 μW·m^-1K^-2 which is 93% higher than a device based on pristine PEDOT：PSS. In addition, the highly conductive composite films were used in Pt-free DSSCs, showing an energy conversion efficiency of 5.4%, which is 21% higher than that of a DSSC based on PEDOT：PSS.
基金supported by the National Key R&D Program of China(2018YFB1500102)the Thousand Talent Program for Young Outstanding Scientists in China+1 种基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21572041 and 21772030)for financial support
文摘Metal halide perovskite solar cells(PSCs)have attracted tremendous attention as an emerging photovoltaic technology due to their high efficiency,low cost and ease of fabrication from earth-abundant materials[1,2].The power conversion efficiencies(PCEs)have been rapidly boosted from 3.8%in the pioneer’s work to a certified 24.2%nowadays in just ten years[3].The PCE breakthroughs in PSCs have mostly adopted full lead-based perovskites(APbX3)with bandgaps of 1.5–1.6 eV.
基金supported by National Natural Science Foundation of China(Grant Nos.61275038 and 11274119)
文摘As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells(PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide(GO)-modified PEDOT:PSS hole transport layer was fabricated by spin-coating a GO solution onto the PEDOT:PSS surface. PSCs fabricated on a GO-modified PEDOT:PSS layer exhibited a power conversion efficiency(PCE) of 15.34%, which is higher than 11.90% of PSCs with the PEDOT:PSS layer.Furthermore, the stability of the PSCs was significantly improved, with the PCE remaining at 83.5% of the initial PCE values after aging for 39 days in air. The hygroscopic PSS material at the PEDOT:PSS surface was partlyremoved during spin-coating with the GO solution, which improves the moisture resistance and decreases the contact barrier between the hole transport layer and perovskite layer. The scattered distribution of the GO at the PEDOT:PSS surface exhibits superior wettability, which helps to form a high-quality perovskite layer with better crystallinity and fewer pin holes. Furthermore, the hole extraction selectivity of the GO further inhibits the carrier recombination at the interface between the perovskite and PEDOT:PSS layers. Therefore, the cooperative interactions of these factors greatly improve the light absorption of the perovskite layer, the carrier transport and collection abilities of the PSCs, and especially the stability of the cells.
文摘Graphene sheets(GNs) have high conductivity, but they exhibit weak electromagnetic(EM) wave absorption performance. Here, poly(3,4-ethylenedioxythiophene)(PEDOT) nanofibers were decorated on the surface of GNs in which the residual defects and groups act as the active sites and therefore are beneficial for the deposition of PEDOT nanofibers.The SEM images display that PEDOT nanofibers are successfully decorated on the surface of GNs through in situ polymerization. The diameter of the PEDOT nanofibers were ranged from 15 to 50 nm with hundreds of nanometers in length. The EM wave absorption properties of graphene, PEDOT, and GNs-PEDOT were also investigated. Compared to pure graphene and PEDOT, the EM wave absorption properties of GNs-PEDOT improved significantly. The maximum value of RLwas up to-48.1 d B at 10.5 GHz with a thickness of only 2 mm. Meanwhile, the absorption bandwidth of RL values below-10 d B was 9.4 GHz(5.8–12.3, 12.9–15.8 GHz) in the thickness of 1.5–3 mm. The enhancement is attributed to the modification of PEDOT and the unique structure of nanofibers. On one hand, the deposition of PEDOT nanofibers on the surface of GNs decreases the conductivity of graphene, and makes impedance match better. On the other hand, the unique structure of PEDOT nanofibers results in relatively large specific surfaces areas, providing more active sites for reflection and scattering of EM waves. Therefore, our findings demonstrate that the deposition of conducting polymers on GNs by non-covalent bond is an efficient way to fabricate strong EM wave absorbers.
文摘The easy oxidation and surface roughness of Cu nanowire （NW） films are the main bottlenecks for their usage in transparent conductive electrodes （TCEs）. Herein, we have developed a facile and scaled-up solution route to prepare Cu NW-based TCEs by embedding Cu NWs into pre-coated smooth poly（3,4-ethylenedioxythiophene）：poly（styrenesulfonate） （PEDOT：PSS） films on poly（ethylene terephthalate） （PET） substrates. The so obtained Cu NW- PEDOT：PSS/PET films have low surface roughness （-70 nm in height）, high stability toward oxidation and good flexibility. The optimal TCEs show a typical sheet resistance of 15Ω·sq-1 at high transparency （76% at A = 550 nm） and have been used successfully to make polymer （poly（3-hexylthiophene）：phenyl-C61- butyric acid methyl ester） solar cells, giving an efficiency of 1.4%. The overall properties of Cu NW-PEDOT：PSS/PET films demonstrate their potential application as a replacement for indium tin oxide in flexible solar cells.
