A facile, rapid, and scalable electrophoretic deposition approach is developed for the fabrication of large-area chemically derived graphene films on conductive substrates based oxide reduced components. Two distinctive approaches fabricating conformal are developed. In first approach, sheets electrophoretically deposited from an aqueous solution after oxidation graphite to subsequent exfoliation oxide. Next, via dip-coating in hydrazine. second nanosheets a strongly alkaline directly onto...

The measured energy diagram for inverted cell architectures perovskite photovoltaic devices is presented. Band offsets are determined in direct and inverse photoemission spectroscopy. films assume a slightly p-type characteristic on top of NiO show good energetic alignment to adjacent organic electron transport layers. finding explains the function gives guidelines optimization. As service our authors readers, this journal provides supporting information supplied by authors. Such materials...

The first-order metal—insulator phase transition in VO2 is characterized by an ultrafast several-orders-of-magnitude change electrical conductivity and optical transmittance, which makes this material attractive candidate for the fabrication of limiting elements, thermochromic coatings, Mott field-effect transistors. Here, we demonstrate that phase-transition temperature hysteresis can be tuned scaling to nanoscale dimensions. A simple hydrothermal protocol yields anisotropic free-standing...

The peculiarities in the electronic structure of seemingly simple binary vanadium oxide VO2, as manifested a pronounced metal−insulator phase transition proximity to room temperature, have made it subject extensive theoretical and experimental investigations over last several decades. We review some recent advances treatments strongly correlated systems along with ultrafast measurements VO2 samples that provide unprecedented mechanistic insight into nature transition. Scaling nanoscale...

The influence of finite size in altering the phase stabilities strongly correlated materials gives rise to interesting prospect achieving additional tunability solid–solid transitions such as those involved metal–insulator switching, ferroelectricity, and superconductivity. We note here some distinctive effects on relative insulating (monoclinic) metallic (tetragonal) phases solid-solution WxV1−xO2. Ensemble differential scanning calorimetry individual nanobelt electrical transport...

The Rashba splitting in hybrid organic-inorganic lead-halide perovskites (HOIP) is particularly promising and yet controversial, due to questions surrounding the presence or absence of inversion symmetry. Here we utilize two-photon absorption spectroscopy study symmetry breaking different phases these materials. This an all-optical technique observe quantify effect as it probes bulk In particular, measure excitation spectra photoluminescence 2D, 3D, anionic mixed HOIP crystals, show that...

The nucleation and growth mechanisms of Li deposits on Si Cu substrates in commercial carbonate electrolyte are detailly presented, which indicates how various design parameters regulate deposit morphology affect battery performance.

The small exciton binding energy of perovskite suggests that the long-lived photoluminescence and slow recovery ground state bleaching tetragonal phase at room temperature results primarily from decay free charges rather than initially created excitons. Here we demonstrate orthorhombic methylammonium lead iodide (CH3NH3PbI3) is much faster using dependent transient absorption spectroscopy. distribution in orientation group which disordered ordered smaller dielectric constant larger latter...

While research on derivatives of both bulk and low-dimensional metal halide perovskite (MHP) semiconductors has grown exponentially over the past decade, understanding intentional applications electronic doping have lagged behind. In this Focus Review, we take a critical look at these challenges by considering different potential routes, advantages pitfalls each route, unique properties MHP systems that may contribute to inherent difficulties realizing successful doping. We specifically...

Abstract Aside from band gap reduction, little is understood about the effect of tin‐for‐lead substitution on fundamental optical and optoelectronic properties metal halide perovskites (MHPs), especially when transitioning 3D to lower dimensional structures. Herein, we take advantage spectroscopic isolation excitons in 2D MHPs study intrinsic differences between lead tin MHPs. The exciton's spectral fine structure indicates a larger polaron binding energy Additionally, electroabsorption...

Abstract The exciton binding energy ( E b ) is a key parameter that governs the physics of many optoelectronic devices. At their best, trustworthy and precise measurements challenge theoreticians to refine models, are driving force in advancing understanding material system, lead efficient device design. worst, inaccurate astray, sow confusion within research community, hinder improvements by leading poor designs. This review article seeks highlight pros cons different measurement techniques...

The substitutional doping of Mo within VO2 substantially alters the electronic and structural phase diagrams host lattice, most notably by bringing technologically relevant metal–insulator transition temperature in closer proximity to room temperature. Here, we have used X-ray absorption fine structure (XAFS) spectroscopy at V K-edges examine local geometric both dopant atoms lattice. A nominal oxidation state +5 has been determined, which implies electron band structure. In addition, XAFS...

We report the assembly of Bi₂S₃ into percolated networks.

Efficient out-of-plane charge transport is required in vertical device architectures, such as organic solar cells and light emitting diodes. Here, we show that graphene, transferred onto different technologically-relevant substrates, can be used to induce face-on molecular stacking improve hole copper phthalocyanine thin films.

Two-dimensional (2D) organic-inorganic hybrid perovskite multiple quantum wells that consist of multilayers alternate organic and inorganic layers exhibit large exciton binding energies order 0.3 eV due to the dielectric confinement between layers. We have investigated characteristics 2D butylammonium lead iodide, (C4H9NH3)2PbI4 using photoluminescence UV-vis absorption in temperature range 10 K 300 K, electroabsorption spectroscopy. The evolution an additional absorption/emission at low...

Methylammonium lead iodide (CH3NH3PbI3) hybrid perovskite in the tetragonal and orthorhombic phases have different exciton binding energies demonstrate excitation kinetics. Here, we explore role that crystal structure plays kinetics via fluence dependent transient absorption spectroscopy. We observe stronger saturation of free carrier concentration under high pump energy density phase relative to phase. attribute this phenomenon small dielectric constant, large energy, weak Coulomb...

Large size cation (PA) was introduced into the grain boundary and film surface of 3D perovskite to improve solar cell efficiency moisture stability.

The ultrafast first-order metal–insulator phase transition in VO2 is characterized by a several orders of magnitude change optical transmittance and electrical conductivity, which makes this material an attractive candidate for use wide variety applications ranging from Mott field-effect transistors to thermochromic coatings waveguides. However, relatively little progress has been achieved fabricating VO2nanostructures exhibiting well-defined despite the potential attractiveness such...

Results from transport measurements in individual $W_{x}V_{1-x}O_{2}$ nanowires with varying extents of $W$ doping are presented. An abrupt thermally driven metal-insulator transition (MIT) is observed these wires and the temperature decreases increasing content at a pronounced rate - (48-56) K/$at.%W$, suggesting significant alteration phase diagram bulk. These can also be through voltage-driven MIT dependence insulator to metal switchings studied. While driving an metal, threshold voltage...

The electronic properties of titanium(IV) sulfide (TiS2) have been scrutinized for many decades due to its strong tendency toward nonstoichiometry with either titanium excess or sulfur deficiency in crystal structure. Here, the systematic solid-state transformation TiS3 TiS2–x nanobelts as a means control nanostructures is reported. Careful structural, optical, and studies were performed elucidate real nature TiS2 (i.e., semimetal semiconductor). Experimental evidence gathered by...

For many decades, bulk Bi2S3, a key low-bandgap metal chalcogenide semiconductor, has lagged behind in terms of potential applications due to its poor electrical properties. As such, controlling size extrinsic atom interactions this material might emerge as viable route enhance Here, we report the hydrothermal synthesis, structural characterization, and optoelectronic properties Bi2S3-xSex solid solutions. Optical characterizations show decrease bandgap Bi2S3 nanowires function Se...

Considerable recent research interest has focused on mapping the structural phase diagrams of anisotropic VO2 nanobeams as model systems for elucidating single-domain behavior within strongly correlated electronic materials, to examine in particular coupling lattice and orbital degrees freedom. Nevertheless, role substitutional doping altering stabilities competing ground states remains underexplored. In this study, we use individual nanowire Raman microprobe progressions underlying...