Reaction Of Metal Precursors Research Articles

Gentle Materials Need Gentle Fabrication: Encapsulation of Perovskites by Gas-Phase Alumina Deposition.

Metal halide perovskites have attracted tremendous attention as promising materials for future-generation optoelectronic devices. Despite their outstanding optical and transport properties, the lack of environmental and operational stability remains a major practical challenge. One of the promising stabilization avenues is metal oxide encapsulation via atomic layer deposition (ALD); however, the unavoidable reaction of metal precursors with the perovskite surface in conventional ALD leads to degradation and restructuring of the perovskites' surfaces. This Perspective highlights the development of a modified gas-phase ALD technique for alumina encapsulation that not only prevents perovskites' degradation but also significantly improves their optical properties and air stability. The correlation between precise atomic interactions at the perovskite-metal oxide interface with the dramatically enhanced optical properties is supported by density functional theory calculations, which also underlines the widespread applicability of this gentle technique for a variety of perovskite nanostructures unbarring potential opportunities offered by combination of these approaches.

Facile Synthesis Of Composition-Controllable PtPdAuTe Nanowires As Superior Electrocatalysts For Direct Methanol Fuel Cells.

Multicomponent Pt-based nanowires (NWs) have attracted widespread attention as eletrocatalysts toward direct alcohol fuel cells because of their unique one-dimensional structure and high reaction dynamics. Quaternary PtPdAuTe NWs are designed via a facile template method, and NWs with a different composition are obtained by adjusting the feed ratio of metal precursors. The direct displacement reaction of metal precursors with Te NWs and the partial oxidation of Te lead to the formation of quaternary NWs. The rough surface and abundant reactive sites deriving from the rearrangement of metal atoms on the Te NWs surface endow the PtPdAuTe NWs with a superior electrocatalytic property and durability for methanol oxidation. The Pt20 Pd20 Au10 Te50 NWs display the largest mass activity and best stability among all catalysts. The preparation of PtPdAuTe NWs could provide a viable strategy for the preparation of other multicomponent NWs.

Synthesis, Structural and Biological Studies of Some Half‐Sandwich d6‐Metal Complexes with Pyrimidine‐Based Ligands

AbstractThe reaction of metal precursors {[Cp*MCl2]2 (M=Rh, Ir)} with 2‐aminopyrimidine (L1) gave binuclear complexes as [(Cp*MCl2)2(μ‐L1)], where L1 acted as a bridging ligand. While 2‐mercaptopyrimidine (L2) with [Cp*MCl2]2 {M=Rh(III), Ir(III)} formed mononuclear di substituted complexes as [Cp*M(L2)2], where L2 acted as a chelating as well as a monodentate ligand. The reaction of [CpRu(PPh3)2Cl] with 2‐mercaptopyrimidine (L2) led to the formation of mononuclear complex as general formula [CpRu(PPh3)(L2)] in presence of a base. 2‐Mercaptopyrimidine ligand resulted complexes with strained four‐membered metallacycle while 2‐aminopyrimidine yielded bridged complexes. HOMO‐LUMO energy gaps and UV‐Visible bands were additionally rationalised by the DFT studies. The binding ability of the complexes to the CT‐DNA was confirmed using UV‐Visible and fluorescence spectroscopy. In vitro antibacterial activity of the complexes was evaluated against human pathogenic bacteria. Cytotoxicity of the complexes was examined by the MTT assay over three cancerous and one non‐cancer cell lines viz., BE, HT‐29, MIA−Pa‐Ca2 and ARPE‐19.

Alternative device structures for CIGS-based solar cells with semi-transparent absorbers

Abstract In this work, we discuss two alternative structures of CIGS-based solar cells, a bi-facial configuration and a back-wall configuration. One of the critical issues in these structures is fabrication of a transparent back contact which facilitates not only ohmic contact for holes in the valance but also an effective reflector for electrons in the conduction band. In order to meet these requirements of the transparent back contact, a p-type amorphous Si (p-a-Si)/intrinsic amorphous Si (i-a-Si) bi-layer was deposited onto the ITO back contact. Absorber films were formed by a metal precursor reaction in H2Se and H2S, and their thicknesses were adjusted to about 0.25 µm to enhance current collection from back-side illumination. The resulting devices with a bi-facial structure of SLG/ITO/p-Si/i-Si/Cu(In, Ga)(Se,S)2/CdS/i-ZnO/ITO/Ni-Al exhibited a comparable open-circuit voltage to a Cu(In, Ga)(Se,S)2 cell on a Mo substrate in tests with illumination of both sides. Back-wall cells with a structure of SLG/ITO/p-Si/i-Si/Cu(In, Ga)(Se,S)2/CdS/i-ZnO/Ag-reflector were also fabricated and improved current collection by greater light trapping was achieved compared to the bi-facial cell with back-side illumination.

A general and rapid approach to hybrid metal nanoparticle–ZnO nanowire arrays and their use as active substrates for surface-enhanced Raman scattering detection

Rapid SERS substrate preparation: an aqueous phase reaction of metal precursors with ZnO@Zn has been exploited for synthesizing SERS-active metal–ZnO nanowire arrays.

Na Incorporation in Cu(In,Ga)(Se,S)<sub>2</sub> Films Grown on Insulator-Coated Stainless Steel Foil Using a Metal Precursor Reaction

Cu(In,Ga)(Se,S)2 (CIGSS) films are formed on flexible 430 stainless steel foils through reacting Cu–In–Ga metal precursors in H2Se and H2S. The foils are coated using an electrically insulating silicone-based resin that can sustain temperatures as high as 600 °C. NaF films with various thicknesses are deposited between the metal precursor and Mo back contact in order to incorporate Na into the CIGSS films. The metal precursor reaction with the extrinsic Na incorporation results in greater Ga homogenization and S incorporation. The higher Na incorporation enhances $V_{{\rm OC}}$ and lowers $J_{{\rm SC}}$ . The temperature-dependent $V_{{\rm OC}}$ and drive-level capacitance profiling measurements reveal that the Na incorporation results in higher activation energy of the recombination and increased carrier density.

Synthesis, Structures and Properties of Novel Platinum(II) Acetylide Complexes and Polymers with Tri(tolyl)phosphine as the Auxiliary Ligand

A new family of luminescent platinum(II) acetylide complexes and polymers were formed by the copper(I) catalyzed reaction of cis-[PtCl2(PR3)2] (R=C6H5–p-CH3) with appropriate acetylide ligands. The reaction of metal precursors with 2.5 equivalents of monoterminal acetylide ligands provided metal complexes trans-[Pt(p-tolyl3P)2(C≡C-R)2] (R=C6H4-p-NO2 (1) C6H4 -p-CH3 (2)), and equimolar amounts of diterminal ligand and metal chloride precursor, under reflux, afforded the metal poly-yne polymers [-Pt(p-tolyl3P)2C≡C–R–C≡C–]n, (R=biphenyl and 2,5-dioctyloxybenzene). Characterization of the newly developed polymer and metal complexes was accomplished by FT-IR, multinuclear NMR (1H, 31P, 13C) and mass spectrometry, as well as elemental analysis. The molecular structure of the metal complex trans-[Pt(p-tolyl3P)2(C≡CC6H4–p-NO2)2] (1) was confirmed by single crystal X-ray crystallography. The electronic absorption and photoluminescence spectra of the metal complexes and polymers have been used to probe their photophysical properties. The studies reveal that the presence of heavy metal atom and substituent groups on the phenyl ring of the ligands can enhance the efficiency of intersystem crossing from the S1 singlet excited state to the T1 triplet excited state and thus give intense phosphorescence.

Composition and bandgap control in Cu(In,Ga)Se2 -based absorbers formed by reaction of metal precursors

Composition and bandgap control in Cu(In,Ga)Se₂ -based absorbers formed by reaction of metal precursors