Triarylamine end-capped-functionalized arylene-imidazole derivatives were synthesized from readily accessible, inexpensive precursors and employed as hole transporting materials (HTMs) in perovskite solar cells (PSCs). All the HTMs displayed high thermal decomposition temperatures (>410 °C), which is beneficial for realizing stable PSC devices. In addition, the new HTMs show appropriate energy level alignment with the perovskite layer, ensuring efficient hole transfer from perovskites to HTMs.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2020
A new organic small-molecule family comprising tetracyanoquinodimethane-substituted quinoidal dithioalky(SR)terthiophenes (s) ( (); SR = SCH, (); SR = SCH, (); SR = SCH) was synthesized and contrasted with a nonthioalkylated analogue ( (); R = CH). The physical, electrochemical, and electrical properties of these new compounds are thoroughly investigated. Optimized geometries obtained from density functional theory calculations and single-crystal X-ray diffraction reveal the planarity of the SR-containing core.
View Article and Find Full Text PDFThree new organic semiconductors with alkyl chain-substituted tetrathienoacene (TTAR) as the central core and both ends capped with thiophene (DT-TTAR), thienothiophene (DTT-TTAR) and dithienothiophene (DDTT-TTAR) have been synthesized and characterized for organic field effect transistor (OFET) applications. A hole mobility of 0.81 cm V s was achieved for the DDTT-TTAR film, which represents the highest mobility yet found for a solution-processable p-type TTAR-based small molecular semiconductors.
View Article and Find Full Text PDFA combination of a solution process and the control of the electric potential for magnetism represents a new approach to operating spintronic devices with a highly controlled efficiency and lower power consumption with reduced production cost. As a paradigmatic example, we investigated Co/Pt(111) in the Bloch-wall regime. The depression in coercive force was detected by applying a negative electric potential in an electrolytic solution.
View Article and Find Full Text PDFThree new donor-π-donor (D-π-D) tetrathienoacene (thieno[2',3':4,5]thieno[3,2-b]thieno[2,3-d]thiophene (TTA))-cored chromophores, end-functionalized with electron-donating triphenylamine (TPA) groups, were developed and characterized for their two-photon-related properties by using both nano- and femtosecond laser pulses as the probing tools. TTA-based chromophores exhibit stronger and more widely dispersed two-photon absorption (2PA) than those of dithienothiophene (DTT)-based congeners. As a consequence, the bithiophene-conjugated TTA chromophore exhibits the highest maximum 2PA cross-section value (up to 2500 GM) with good thermal stability, and thus, it is the best performing two-photon chromophore among the studied model compounds.
View Article and Find Full Text PDFVoltammetry and in-situ scanning tunneling microscopy (STM) were used to examine electrodeposition of cobalt (Co) on a stationary Pt(111) electrode in 0.1 M K2SO4 + 1 mM H2SO4 + 10 mM CoSO4 (or the sulfate solution) without and with 10 mM chloride (the chloride solution). Under- and overpotential deposition (UPD and OPD) of Co resulted in reduction peaks at -0.
View Article and Find Full Text PDFThe adsorption and desorption of bis-(3-sulfopropyl) disulfide (SPS) on Cu and Au electrodes and its electrochemical effect on Cu deposition and dissolution were examined using cyclic voltammetry stripping (CVS), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). SPS dissociates into 3-mercapto-1-propanesulfonate when it is contacted with Au and Cu electrodes, producing Cu(I)- and Au(I)-thiolate species. These thiolates couple with chloride ions and promote not only the reduction of Cu(2+) in Cu deposition but also the oxidation of Cu(0) to Cu(+) in Cu stripping.
View Article and Find Full Text PDFThis study employed real-time in situ STM imaging to examine the adsorption of PEG molecules on Pt(111) modified by a monolayer of copper adatoms and the subsequent bulk Cu deposition in 1 M H(2)SO(4) + 1 mM CuSO(4)+ 1 mM KCl + 88 μM PEG. At the end of Cu underpotential deposition (~0.35 V vs Ag/AgCl), a highly ordered Pt(111)-(√3 × √7)-Cu + HSO(4)(-) structure was observed in 1 M H(2)SO(4) + 1 mM CuSO(4).
View Article and Find Full Text PDFThe adsorption of bis-3-sodiumsulfopropyldi-sulfide (SPS) on metal electrodes in chloride-containing media has been intensively studied to unveil its accelerating effect on Cu electrodeposition. Molecular resolution scanning tunneling microscopy (STM) imaging technique was used in this study to explore the adsorption and decomposition of SPS molecules concurring with the electrodeposition of copper on an ordered Pt(111) electrode in 0.1 M HClO(4) + 1 mM Cu(ClO(4))(2) + 1 mM KCl.
View Article and Find Full Text PDFIn situ scanning tunneling microscopy (STM) was used to reveal the structures of dithieno[2,3-b:3,2-d]thiophene diphenyl (DTT) molecules deposited onto Au(111) electrode from a dosing solution made of dichlorobenzene and 50 muM DTT. Potential control was proven to be of prime importance in guiding the arrangement of DTT admolecules on Au(111) in 0.1 M HClO(4), as disorder DTT adlayer seen at E > 0.
View Article and Find Full Text PDFIn situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV) were used to study the adsorption of 3-mercapto-1-propanesulfonic acid (MPS) and bis(3-sulfopropyl)-disulfide (SPS) on Au(111) electrode in a HClO(4) aqueous solution. Chloride ions were introduced into the electrolyte solution, and their effect on the adsorption behavior of MPS and SPS was investigated. The CV results show that SPS and MPS molecules preferentially adsorb on the Au(111) surface compared to chloride ions, and furthermore, chloride ion can induce the adsorption of thiol molecules on the Au(111) surface.
View Article and Find Full Text PDFCyclic voltammetry (CV) and in situ scanning tunneling microscopy (STM) were employed to study the adsorption and polymerization of the geometric isomers of ethylaniline (EA) on a Au(111) single-crystal electrode in 0.5 M H(2)SO(4). All three isomers, namely o-, m-, and p-EA, were adsorbed in highly ordered structures, identified as Au(111)-(4 x 2 square root(3))rect for m- and p-EA and (4 square root(3) x 4 square root(3))R30 degrees for o-EA, at the onset potentials (approximately 0.
View Article and Find Full Text PDFWe have used electrochemical scanning tunneling microscopy (EC-STM) to obtain molecular insights on the adlayer structures and electrochemical polymerization of 3,4-ethylenedioxythiophene (EDOT) on a bare Au(111) single crystal electrode in 0.1 M HClO(4) solution. Cyclic voltammetric (CV) studies showed an increase in anodic current at 0.
View Article and Find Full Text PDFThe adsorption of 3,3'''-dihexyl-2,2':5',2'':5'',2'''-quaterthiophene (4T) molecules on an Au(111) electrode was examined by using in situ scanning tunneling microscopy in 0.10 M HClO(4), revealing internal molecular structures of the tetrathiophene backbones and the hexyl side chains. The 4T admolecules were packed in lamellae with their molecular axis aligned along the main axis of the Au(111) substrate and their hexyl side chains interdigitated to enhance intermolecular interaction.
View Article and Find Full Text PDFThe adsorption of hexahexylduodecithiophene (12T) on a Au(111) electrode was investigated by using cyclic voltammetry (CV) and in situ electrochemical scanning tunneling microscopy (EC-STM) in 0.10 M HClO(4). Potential control at 0.
View Article and Find Full Text PDFIn situ scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure (NEXAFS) have been used to examine the conformation of a monolayer of polyaniline (PAN) molecules produced on a Au(111) single-crystal electrode by anodization at 1.0 V [vs reversible hydrogen electrode (RHE)] in 0.10 M H(2)SO(4) containing 0.
View Article and Find Full Text PDF3-Mercapto-1-propanesulfonic acid (MPS) and bis(3-sulfopropyl) disulfide (SPS) adsorbed on a Au(111) electrode were studied by using in situ scanning tunneling microscopy (STM). Although the adsorptions of MPS and SPS are known to be oxidative and reductive, respectively, on an Au(111) electrode, these two admolecules behave similarly in terms of phase evolution, surface coverage, potential for stripping, and characteristics of cyclic voltammetry. However, different adsorption mechanisms of these molecules result in different structures.
View Article and Find Full Text PDFElectrochemical scanning tunneling microscopy (ECSTM) has been used to examine the adlayer of octa-alkoxy-substituted copper(II) phthalocyanines (CuPc(OC(8)H(17))(8)) on Au(111) in 0.1 M HClO(4), where the molecular adlayer was prepared by spontaneous adsorption from a benzene solution containing this molecule. Topography STM scans revealed long-range ordered, interweaved arrays of CuPc(OC(8)H(17))(8) with coexistent rectangular and hexagonal symmetries.
View Article and Find Full Text PDFIn situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV) were employed to examine the underpotential deposition (UPD) of cadmium on a rhodium(111) electrode in sulfuric and hydrochloric acids. The (bi)sulfate and chloride anions in the electrolytes played a main role in controlling the number and arrangement of Cd adatoms. Deposition of Cd along with hydrogen adsorption occurred near 0.
View Article and Find Full Text PDFCyclic voltammetry (CV) and in situ scanning tunneling microscopy (STM) were used to examine four dithiol molecules, including 1,6-hexanedithiol, 1,9-nonanedithiol, 1,2-benzenedithiol, and 1,3-benzenedithiol, adsorbed on well-ordered Pt(111) electrodes in 0.1 M HClO(4). The open-circuit potential (OCP) of Pt(111) electrodes decreased substantially from 0.
View Article and Find Full Text PDFIn-situ scanning tunneling microscopy (STM), cyclic voltammetry (CV), and infrared reflection-adsorption spectroscopy (IRRAS) have been used to examine the electrodeposition of gold onto Pt(111) electrodes modified with benzenethiol (BT) and benzene-1,2-dithiol (BDT) in 0.1 M HClO4 containing 10 microM HAuCl4. Both BT and BDT were attached to Pt(111) via one sulfur headgroup.
View Article and Find Full Text PDFSubstituted bis(phthalocyaninato) rare earth complexes ML2 (M = Y and Ce; L = [Pc(OC8H17)8]2, where Pc = phthalocyaninato) were adsorbed onto single crystalline Au(111) electrodes from benzene saturated with either YL2 or CeL2 complex at room temperature. In situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV) were used to examine the structures and the redox reactions of these admolecules on Au(111) electrodes in 0.1 mol dm(-3) HClO4.
View Article and Find Full Text PDFIn situ scanning tunneling microscopy (STM) combined with linear sweep voltammetry was used to examine spatial structures of sulfur adatoms (SA) and benzenethiol (BT) molecules adsorbed on an ordered Ru(0001) electrode in 0.1 M HClO4. The Ru(0001) surface, prepared by mechanical polishing and electrochemical reduction at -1.
View Article and Find Full Text PDFThe adsorption of formaldehyde (HCHO) on Pt(111) and Pt(100) electrodes was examined by cyclic voltammetry (CV) and in situ scanning tunneling microscopy (STM) in 0.1 M HClO(4). The extent of HCHO adsorption at both Pt electrodes was evaluated by comparing the CVs, particularly for the hydrogen adsorption and desorption between 0.
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