Superlattice Electrodes Research Articles

A Volume Self-Regulation MoS2 Superstructure Cathode for Stable and High Mass-Loaded Zn-Ion Storage.

Engineering multifunctional superstructure cathodes to conquer the critical issue of sluggish kinetics and large volume changes associated with divalent Zn-ion intercalation reactions is highly desirable for boosting practical Zn-ion battery applications. Herein, it is demonstrated that a MoS2/C19H42N+ (CTAB) superstructure can be rationally designed as a stable and high-rate cathode. Incorporation of soft organic CTAB into a rigid MoS2 host forming the superlattice structure not only effectively initiates and smooths Zn2+ transport paths by significantly expanding the MoS2 interlayer spacing (1.0 nm) but also endows structural stability to accommodate Zn2+ storage with expansion along the MoS2 in-plane, while synchronous shrinkage along the superlattice interlayer achieves volume self-regulation of the whole cathode, as evidenced by in situ synchrotron X-ray diffraction and substantial ex situ characterizations. Consequently, the optimized superlattice cathode delivers high-rate performance, long-term cycling stability (∼92.8% capacity retention at 10 A g-1 after 2100 cycles), and favorable flexibility in a pouch cell. Moreover, a decent areal capacity (0.87 mAh cm-2) is achieved even after a 10-fold increase of loading mass (∼11.5 mg cm-2), which is of great significance for practical applications. This work highlights the design of multifunctional superlattice electrodes for high-performance aqueous batteries.

Super-stretchable polymer-AgPdCu superlattice electrodes for high-performance wearable electronics

Highly-stretchable and semi-transparent polytetrafluoroethylene (PTFE)/AgPdCu (APC)-PTFE-based superlattice electrodes were realized by alternately sputtering very thin APC-PTFE hybrid layers on a polyurethane (PU) substrate at room temperature. The electrical and mechanical properties of the superlattice electrodes were optimized by controlling the PTFE thickness and the number of layers of the stacked superlattice. The optimal PTFE/APC-PTFE/PTFE/APC-PTFE/PTFE superlattice electrode showed a sheet resistance of 8.5 Ohm/square and maintained a high conductivity, even at a strain of 100%. The outstanding mechanical stretchability of the superlattice electrode is attributed to the 3-dimensional conductive APC network structure in the PTFE polymer matrix . In addition, the external strain applied to the superlattice electrode led to a change in the optical transmittance that could be used for optical switching in stretchable electronics. The superlattice electrodes can be utilized to fabricate stretchable electroluminescent devices, stretchable thin film heaters, and wearable temperature sensors . This successful demonstration of stretchable devices that include highly stretchable superlattice electrodes demonstrated the feasibility of this manufacturing strategy for use in next-generation stretchable and wearable electronics . • Fabrication of highly conductive and stretchable metal-polymer 3D nanocomposites by continuous co-sputtering of polymer and metal target. • The number of stacked layers and thickness of the polymer and polymer-metal hybrid films were controlled to form an alternating superlattice structure. • The optimized electrode showed a sheet resistance of 8.5 Ohm/square, an average transmittance of 34.0% for visible light, and stretchability that reversibly maintained a high conductivity at up to 100% strain. • The optimized electrode was applied as stretchable thin-film heater, electroluminescent device, and wearable temperature sensor.

Versatile Solution‐Processed Organic–Inorganic Hybrid Superlattices for Ultraflexible and Transparent High‐Performance Optoelectronic Devices

AbstractCrystalline or amorphous metal oxides are widely used in various optoelectronic devices as key components, such as transparent conductive electrodes, dielectrics or semiconducting active layers for thin‐film transistor (TFT) backplanes in large‐area displays, photovoltaics, and light‐emitting diodes. Although crystalline inorganic materials demonstrate outstanding optoelectronic performance, owing to their wide bandgaps, large conductivities, and high carrier mobilities, their inherent brittleness makes them vulnerable to mechanical stress, thereby limiting the use of metal‐oxide films in emerging flexible electronic applications. In this study, stress‐diffusive organic–inorganic hybrid superlattice nanostructures are developed to overcome the mechanical limitation of crystalline oxides and to provide high mechanical stability to metal‐oxide semiconductors. In particular, hybrid transparent superlattice electrodes based on crystalline indium–tin oxide exhibit high electrical conductivities of up to 555 S cm–1 (resistance variation < 3%) and effectively reduce the mechanical stress on the inorganic layer (up to 10 000 bending cycles with a radius of 1 mm). Furthermore, to ensure the viability of the hybrid superlattice flexible electronics, all solution‐processed superlattice crystalline indium–gallium‐oxide TFTs are implemented on a thin (≈5 µm) polyimide substrate, providing highly robust and excellent electrical performance (average mobility of 7.6 cm2 V–1 s–1).

Molecular-scale heteroassembly of redoxable hydroxide nanosheets and conductive graphene into superlattice composites for high-performance supercapacitors.

Artificial superlattice nanocomposites are successfully prepared by electrostatic heteroassembly of redoxable Co-Al or Co-Ni layered double hydroxide (LDH) nanosheets with graphene. The superlattice electrodes exhibit a high capacity up to ca. 650 F/g, which is approximately 6 times that of pure graphene. The composites are found to be capable of superfast charging and discharging, up to ca. 100 Hz, comparable with the high-power performance of graphene electrodes.

Electrochemical preparation of ZnS/CdS superlattice and its photoelectrochemical properties

Superlattice electrodes composed of three molecular layers of CdS and one to three molecular layers of ZnS were prepared on gold (111) film by using electrochemical atomic layer epitaxy. The prepared electrodes exhibited similar behavior to those of n-type semiconductor electrodes. The energy gap was not changed at all by changing the number of molecular layers of ZnS and by increasing the number of periods in the superlattice structure up to four. The magnitude of the anodic photocurrent was, however, influenced by these variables. It increased with an increase in the number of periods in the superlattice structure and decreased with increasing number of molecular layers of ZnS.

Electrochemistry of GaAs/AlGaAs superlattice electrodes in acetonitrile solutions with metallocene redox couples

Abstract The photoelectrochemical properties of novel GaAs/AlGaAs superlattice electrodes were investigated in nonaqueous solutions containing reversible and irreversible redox couples. The superlattice materials consisted of 35 alternating layers of 17 A Al 0.35 Ga 0.65 As and 150 A GaAs grown onto a highly doped p -GaAs substrate. Under illumination, the superlattice electrodes exhibited current/potential curves with hysteresis in decamethylferrocene +/0 solutions. The hysteresis was due to photoinduced dark current associated with hole injection into the valence band of the semiconductor. More reducing couples such as cobaltocene +/0 and dicarbomethoxycobaltocene +/0 afforded stable current/potential curves with the superlattice electrodes. The irreversible homogeneous and electrochemical reduction of a series of vicinal dibromides was investigated in order to develop a redox system capable of detecting hot electron reactions.

Photoelectrochemical Behavior of the GaAs/AlxGa1-x As Superlattice Electrode/Electrolyte Interface

Single and multiple quantum wells of lattice-matched superlattices material GaAs/AlxGa1-x As have been studied as photoelectrodes in photoelectrochemical cells containing nonaqueous electrolyte. Structured photocurrent spectra in the potential range of -1.8 to 1.0 V (vs standard calomel electrode) were obtained. The quantum yields for both superlattice electrodes were estimated and compared.

Photoelectrochemistry of strained-layer and lattice-matched superlattice electrodes: effects due to buffer layers

Strained-layer and lattice-matched superlattice electrodes have been studied and compared as photoelectrodes in photoelectrochemical cells, and the effects of the presence of buffer layers in the strained-layer systems have been established. Photocurrent spectroscopy and photomodulated reflectance spectroscopy of superlattice electrodes, etched superlattice electrodes, and buffer layer structures reveal that highly strained superlattices (1.8% mismatch) have poorly defined quantization effects in their quantum wells; strained-layer superlattices with less mismatch (0.9%) have better defined quantization, but this is not reflected in their photocurrent spectra. On the other hand, lattice-matched superlattice electrodes exhibit extremely well-defined quantization effects that are clearly exhibited in multiple photocurrent peaks that match theoretical predictions; photomodulated reflectance spectra exhibit 17 transitions that represent all the possible allowed transitions in the quantum wells, including all light and heavy hole transitions, as well as unconfined transitions above the well barriers. The present work indicates that previous results reported for the photoelectrochemistry of highly strained superlattices probably reflected a photoresponse that was influenced more by the buffer layers than by the superlattice layers. The occurrence of hot electron transfer from photoexcited superlattice electrodes remains to be demonstrated unequivocally.

Kinetics of electron transfer from photoexcited superlattice electrodes

Kinetics of electron transfer from photoexcited superlattice electrodes

Photocurrent spectroscopy of lattice-matched superlattice electrodes in photoelectrochemical cells

Photocurrent spectra of GaAs/Al0.38Ga0.62As lattice-matched superlattice electrodes were obtained in photoelectrochemical cells containing nonaqueous liquid electrolyte; spectra were compared for two electron acceptors, cobalticinium and ferrocinium, having redox potentials (energy levels) that differ by 1.33 V. The spectra were found to be independent of acceptor energy levels, in sharp contrast to previous results with GaAs/GaAs0.5P0.5As strained-layer superlattices. These results indicate that for lattice-matched systems hot-electron transfer from upper quantum states in the quantum wells is not a dominant process. This is explained by the much lower surface trapping rates in lattice-matched superlattices compared to strained-layer superlattices.

Stabilization and Photoluminescent Characterization of n ‐ GaP / n ‐ GaAs0.4 P 0.6 Strained‐Layer Superlattice Electrodes

not Available.

Quantization effects in the photocurrent spectroscopy of superlattice electrodes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTQuantization effects in the photocurrent spectroscopy of superlattice electrodesA. J. Nozik, B. R. Thacker, J. A. Turner, and J. M. OlsonCite this: J. Am. Chem. Soc. 1985, 107, 26, 7805–7810Publication Date (Print):December 1, 1985Publication History Published online1 May 2002Published inissue 1 December 1985https://doi.org/10.1021/ja00312a001RIGHTS & PERMISSIONSArticle Views131Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (750 KB) Get e-Alerts Get e-Alerts

Stabilization and luminescent properties of GaP/GaAs0.4P0.6 strained-layer superlattice electrodes

Photoelectrochemical cells based on n-GaP/n-GaAs0.4P0.6 strained-layer superlattice (SLS) electrodes have been stabilized against photocorrosion in an aqueous (di) telluride electrolyte, and show monochromatic optical to electrical energy conversion efficiencies of a few percent. The near-band-gap photoluminescence (PL) of the SLS electrodes exhibits field-induced quenching in rough accord with a dead-layer model. Electroluminescence (EL) is observed when the SLS’s are used as cathodes in a formamide/Na2S2O8 electrolyte. The EL and PL spectral distributions are similar.