- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Unraveling Doping Capability of Conjugated Polymers for Strategic Manipulation of Electric Dipole Layer toward Efficient Charge Collection in Perovskite Solar Cells
摘要： Developing electrical organic conductors is challenging because of the difficulties involved in generating free charge carriers through chemical doping. To devise a novel doping platform, the doping capabilities of four designed conjugated polymers (CPs) are quantitatively characterized using an AC Hall-effect device. The resulting carrier density is related to the degree of electronic coupling between the CP repeating unit and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), and doped PIDF-BT provides an outstanding electrical conductivity, exceeding 210 S cm?1, mainly due to the doping-assisted facile carrier generation and relatively fast carrier mobility. In addition, it is noted that a slight increment in the electron-withdrawing ability of the repeating unit in each CP diminishes electronic coupling with F4-TCNQ, and severely deteriorates the doping efficiency including the alteration of operating doping mechanism for the CPs. Furthermore, when PIDF-BT with high doping capability is applied to the hole transporting layer, with F4-TCNQ as the interfacial doping layer at the interface with perovskite, the power conversion efficiency of the perovskite solar cell improves significantly, from 17.4% to over 20%, owing to the ameliorated charge-collection efficiency. X-ray photoelectron spectroscopy and Kelvin probe analyses verify that the improved solar cell performance originates from the increase in the built-in potential because of the generation of electric dipole layer.
关键词： conjugated polymers,conducting polymers,doping,molecular electronics,solar cells
更新于2025-09-23 15:21:01
-
Synthesis and Electropolymerization of Furan End?capped Dibenzothiophene/Dibenzofuran and Electrochromic Properties of Their Polymers
摘要： Two furan end?capped dibenzothiophene/dibenzofuran five?membered ring monomers, 2,8?bis?(furan?2?yl)?dibenzothiophene (DBT?Fu) and 2,8?bis?(furan?2?yl)?dibenzofuran (DBF?Fu) were successfully synthesized via Stille couple reaction. Corresponding polymers, P(DBT?Fu) and P(DBF?Fu), were obtained by employed the electropolymerization. The surface morphology, electrochemical and optical properties of monomers and polymers were researched by cyclic voltammetry (CV), scanning electron microscopy (SEM), and UV?via spectra method. Both polymers exhibited obvious color changes from neutral state to oxidation state (from green?yellow to dark grey for P(DBT?Fu) and from beige to celadon for P(DBF?Fu)).
关键词： electrochromism,conducting polymers,furan,electropolymerization,dibenzothiophene/furan
更新于2025-09-23 15:21:01
-
Synthesis, electrochromic characterization and solar cell application of thiophene bearing alternating copolymers with azobenzene and coumarin subunits
摘要： In this study, azobenzene and coumarin functionalized thiophene comprising two copolymers (poly (4-((3000-hexyl-[2,20:50,200:500,2000-tetrathiophene] (cid:2) 30-yl)methoxy) - 2H-chromen-2-one (P1) and poly (1-(4-((4000-hexyl-[2,20: 50, 200: 500, 2000 - tetrathiophene] (cid:2) 30-yl) methoxy) phenyl) (cid:2)2-phenyldiazene) (P2)), were designed and synthesized according to the donor–acceptor (D–A) approach to investigate their electrochemical, optical and photovoltaic behaviors. Among the various copolymerization methods to obtain P1 and P2, Stille copolymerization reaction was preferred. The HOMO and LUMO values were determined via cyclic voltammetry (CV) as (cid:2)5.64 eV and (cid:2)3.76 eV for P1 and (cid:2)5.47 eV and (cid:2)3.83 eV for P2, respectively. The optical band gaps of the polymers for P1 and P2 were calculated as 1.88 eV and 1.64 eV using UV-VIS spectrophotometer. Electrochemical and spectroelectrochemical studies for synthesized copolymers support their usage in organic solar cell applications. The organic solar cells (OSCs) were designed using polymer as an electron donor group and PC60BM as an electron acceptor group. Performances of OSCs based on P1 and P2 were investigated with the device structure of ITO/PEDOT:PSS/ Polymer(P1/P2):PC60BM/LiF/Al. The preliminary solar cell results were reported here and studies are going on in our laboratories to increase the efficiency. The highest power conversion efficiency was obtained as 0.81% for P1 based device with 0.47 V open-circuit voltage (Voc) and 4.92 mA/cm2 current density (Jsc) values. The highest efficiency for P2 comprising device was found to be 0.96% under optimum conditions with 0.60 V and 4.98 mA/cm2, Voc and Jsc values, respectively.
关键词： Azobenzene,solar cell,coumarin,conducting polymers,thiophene bearing copolymers
更新于2025-09-23 15:19:57
-
Graphenea??based polymer composites with ultraa??high ina??plane thermal conductivity: A comparison study between optothermal Raman spectroscopy and laser flash method
摘要： We developed a simple solution mixing and molding process for the incorporation of graphene nano-flakes (GNFs) in polymer films. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(ethylene-co-methacrylic acid) (PEMAA) were used for preparation of the samples. The orientation and stacking of GNFs were confirmed using a scanning electron microscope. The thermal conductivity values for these composites were obtained using (1) laser flash method (commercially available) and (2) an optothermal Raman (OTR) technique (homemade device). The former measures the thermal diffusivity (α) and one needs to measure the density (ρ) and the heat capacity (Cp) of the composites in order to measure the in-plane thermal conductivity (κ = α.ρ.Cp), while the latter measures the in-plane thermal conductivity directly from the relation between the excitation power and the position of the Raman resonance. The data obtained from Raman spectroscopy were analyzed, assuming heat propagation in three and two dimensions. The Raman results obtained based on the two-dimensional model were very close to the results obtained using the laser flash method with less than 10% difference. The OTR spectroscopy was found to be a promising technique for measuring the in-plane thermal conductivity of carbon-based polymer composites. PVDF-HFP and PEMAA composite films with very high in-plane thermal conductivity (25 W m?1 K?1) were obtained through the incorporation of GNFs (20 wt % concentration). Considering a very low thermal conductivity of these polymers (<0.2 W m?1 K?1), this corresponds to a large enhancement of roughly 12 400%. ? 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48927.
关键词： nanotubes,conducting polymers,fullerenes,graphene,thermal properties,composites
更新于2025-09-19 17:13:59
-
Fabrication of an Efficient Planar Organic-Silicon Hybrid Solar Cell with a 150 nm Thick Film of PEDOT: PSS
摘要： Organic–inorganic hybrid solar cells composed of p-type conducting polymer poly (3,4-ethylene-dioxythiophene): polystyrenesulfonate (PEDOT: PSS) and n-type silicon (Si) have gained considerable interest in recent years. From this viewpoint, we present an e?cient hybrid solar cell based on PEDOT: PSS and the planar Si substrate (1 0 0) with the simplest and cost-e?ective experimental procedures. We study and optimize the thickness of the PEDOT: PSS ?lm to improve the overall performance of the device. We also study the e?ect of ethylene glycol (EG) by employing a di?erent wt % as a solvent in the PEDOT: PSS to improve the device’s performance. Silver (Ag) was deposited by electron beam evaporation as the front and rear contacts for the solar cell device. The whole fabrication process was completed in less than three hours. A power conversion e?ciency (PCE) of 5.1%, an open circuit voltage (Voc) of 598 mV, and a ?ll factor (FF) of 58% were achieved.
关键词： single junction solar cells,conducting polymers,hybrid solar cells,ethylene glycol,cost effective
更新于2025-09-16 10:30:52
-
Medium Effect on the Electropolymerization and Electro-optical Properties of PEDOS
摘要： 3,4-Ethylenedioxyselenophene (EDOS), an important derivative of 3,4-ethylenedioxythiophene (EDOT), has better optoelectronic properties including lower band gap, better interchain charge transfer, lower oxidation and reduction potentials. In this work, the electropolymerization behavior of EDOS, and the electrochemistry, surface morphology, optical and electrochromic properties of the resultant PEDOS films are comparatively investigated in different solvent-electrolyte systems (CH2Cl2-Bu4NPF6, CH2Cl2-BmimPF6, and pure BmimPF6). We find that solvent-electrolyte systems exert influence on the electropolymerization behavior of EDOS monomer. EDOS displays lower onset oxidation potentials in CH2Cl2-BmimPF6 and pure BmimPF6 than commonly employed CH2Cl2-Bu4NPF6. PEDOS can be facilely electrodeposited in all these systems. Electrochromic results suggest that PEDOS film resulted from CH2Cl2-Bu4NPF6 medium exhibit relatively good transmittance changes (△T%) of 26.5%, high coloration efficiency of 80 cm2 C-1. However, the addition of BmimPF6 reveal a compact morphology, and enhanced the electrochemical stability and open circuit memory for PEDOS film. From these results, PEDOS can be further explored as electrochromic materials towards indoor electrochromic products and flexible displays.
关键词： 3,4-Ethylenedioxyselenophene,Electropolymerization,Electrochromics,Conducting polymers,Medium Effect
更新于2025-09-11 14:15:04
-
Reference Module in Materials Science and Materials Engineering || Chemical and Biological Sensors from Conducting and Semiconducting Polymers
摘要： The need for cheaper, faster, and more accurate measurements in chemical and biological fields has been a driving force for the development of new sensing devices: chemical and biological sensors. These analytical devices comprise a chemical or a biological recognition element, able to interact specifically with an analyte or a target, and a transducer, which converts the recognition event into a measurable signal. On the basis of the transduction principle, chemical and biological sensors can be classified into three major classes: electrochemical, optical, and piezoelectric. The possible range of analytes is almost limitless: from simple molecules to very complex ones.
关键词： electrochemical,biological sensors,optical,chemical sensors,semiconducting polymers,conducting polymers,piezoelectric
更新于2025-09-10 09:29:36
-
Synthesis and Characterization of Four Random copolymers Containing Fluorene as Electron Donors and Benzotriazole, Benzothiadiazole, Pyrido[3,4-b]pyrazine as Electron Acceptors
摘要： Four random copolymers containing fluorene as electron donors and benzotriazole, benzothiadiazole, pyrido[3,4-b]pyrazine as electron acceptors were successfully synthesized. Afterwards, a series of characterization, including cyclic voltammetry (CV), spectroelectrochemistry, kinetics, colorimetry and thermal gravimetric analysis were carried out to fully investigate the properties of the copolymers we got. Their band gaps are 1.87 eV, 1.91 eV, 1.97 eV and 1.98 eV, respectively. From neutral state to oxidized state, PFPP changes from thistle to transparent gray, PBTFPP changes from tan to transparent gray, PBTFBD changes from sienna to lightslategray, and PBDFBD changes from rosybrown to lightgrey. The coloration efficiencies are 269.91cm2·C-1 for PFPP, 177.45cm2·C-1 for PBTFPP, 241.92cm2·C-1 for PBTFBD, and 174.67cm2·C-1 for PBDFBD in near infrared region. Except for PFPP, all the other three copolymers are stable and could be good candidates in electrochromic application.
关键词： benzothiadiazole,fluorene,benzotriazole,conducting polymers,pyrido[3,4-b]pyrazine
更新于2025-09-10 09:29:36
-
[Polymers and Polymeric Composites: A Reference Series] Functional Polymers || Conducting Polymer Nanocomposites as Gas Sensors
摘要： The great concerns regarding environmental and living beings protection together with the widespread requirements for highly accurate process monitoring have highlighted the need for the development of new and sensitive sensors. Conducting polymers and their nanocomposites have been used widely as sensing materials owing to their special redox chemistry. The electrical properties can be controlled easily by doping and undoping processes resulting into the generation of conducting and nonconducting states, respectively. The electrical conductivity also depends on the type and amount of filler (nanosize filler in some cases) used which produces the positive or negative carriers responsible for the conduction. Any type of interaction of these polymers that affects the number and movement of charge carriers affects the conductivity and is the main principle behind the gas sensing characteristics. Advances in nanotechnology allows for the fabrication of various conducting polymer nanocomposites using different techniques. Conducting polymer nanocomposites have high surface area, small dimension, and show enhanced properties, making them suitable for various sensor devices. This chapter presents the different types of gas sensors based on the conducting polymer (polyaniline, polypyrrole, and polythiophene)-based nanocomposites, their progress, and future scope of ongoing research in this research area. The factors that affect the performance of the gas sensors and the chemistry of the sensing process are also addressed.
关键词： Conducting polymers,Undoping,Doping,Polythiophene,Environmental conditions,Polypyrrole,Surface area,Nanocomposites,Polyaniline,Gas sensors
更新于2025-09-10 09:29:36
-
Reduction of specific contact resistance between the conducting polymer PEDOT:PSS and a metal electrode by addition of a second solvent during film formation and a post-surface treatment
摘要： The contact resistance at conducting polymer-electrode junctions could substantially affect device performance because electrical currents or signals generated in the polymer devices must be transferred in their final form through the junctions to the connected load or devices. We report here the specific contact resistance between the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and a metal electrode as measured by a transmission line technique. Toward developing printed electronics that do not require vacuum processes, we focus on the specific contact-resistance, rc, between PEDOT:PSS films and metal pastes. Addition of a second solvent such as ethylene glycol (EG), poly-ethylene glycol (PEG), and dimethyl sulfoxide (DMSO) to PEDOT:PSS solution for film formation induced a significant reduction of rc together with an enhancement of electrical conductivity. A surface treatment using EG or DMSO on electrode areas of the film also decreased rc at the PEDOT:PSS-Ag paste junction to the value at the PEDOT:PSS-Ag junction formed by electron-beam evaporation. The mechanism of reduction of rc is discussed based on morphology of the PEDOT:PSS film.
关键词： Conducting polymers,Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate),Specific contact-resistance
更新于2025-09-10 09:29:36