Covalent Grafting of Dielectric Films on Cu(111) Surface via Electrochemical Reduction of Aryl Diazonium Salts

Abstract

Covalent grafting of dielectric films containing polyhedral oligomeric silsesquioxane (POSS) on the surface of Cu(111) is performed by a one-step electrochemical reduction of diazonium salts. This method is efficient and economic and performs in a proton-polar solvent of deionized water and tetrahydrofuran (THF), where the monomer employs an octavinylsilsesquioxane (OVS) containing a POSS core. The eight vinyl bonds contained in OVS are used to participate in aryl radical-initiated polymerization reactions to form films. The formed film is dense and covers the copper surface completely and uniformly. The thickness of the film can be controlled by adjusting the reaction time. The components of the films are mainly polynitrophenyl (PNP) or polyaminophenyl (PAP) as well as poly(octavinylsilsesquioxane) (POVS), and the POVS content could be adjusted by the applied voltage. The introduction of POSS prevents the copper surface from being oxidized and often gives the film good properties such as good dielectric properties, mechanical properties, and thermal properties. In addition, the presence of Cu–O–C and Cu–C bonds between the film and copper interface is confirmed at different film thicknesses by X-ray photoelectron spectroscopy (XPS), which allowed the construction of covalent bonds between metal and nonmetal, further enhancing the bonding between the film and copper. Organic films prepared by electrochemical reduction of diazonium salts using OVS as a monomer will have potential significance for the future development of the electronics industry.

Surface Functionalized Titanium Nitride Electrode for CMOS Compatible Bioelectronic Devices

“…Further detailed analysis of the changes in the intensity of the C 1s peaks after different modification cycles primarily reveals the presence of “C−N”, “C−O”, and “C−C” bonds. In addition, although the presence of “C‐metal” covalent bonds with a binding energy level of approximately 282 eV is not observed, it is plausible that TiN surfaces undergo passivation and subsequently establish connections through the formation of “Ti−O−C” [9b,27a] . The grafting of diazonium salts onto metal surfaces through “metal‐O−C” covalent bonds has been previously reported and is considered feasible on TiN surfaces containing TiO 2 and TiO x N y components [22a,33] .…”

Flexible Copper Films Modification via Spontaneous Reduction of Aryldiazonium Gold Salts: Unraveling Surface Properties and Energy Profile

“…The Cu 2p narrow scan region shows a modified copper state along with metallic Cu(0) at 932.6 and 952.3 eV, with a shoulder shift at high binding energies, Figure c. Cu 2p 3/2 shows as a shoulder at 934.8 eV on both modified films accompanied by the appearance of shakeup satellite peaks which indicates the presence of Cu(II) ions . Moreover, the deconvolution of Cu 2p high-resolution scans, depicted in Figure S5, shows the Cu(0) peak for Au-COOH@Cu is centered at 932.6 eV, while for Au-NO 2 @Cu is centered at 932.4 eV, which reveals a 0.2 eV positive shift in Au-COOH@Cu.…”

“…Cu 2p 3/2 shows as a shoulder at 934.8 eV on both modified films accompanied by the appearance of shakeup satellite peaks which indicates the presence of Cu(II) ions. 25 Moreover, the deconvolution of Cu 2p high-resolution scans, depicted in Figure S5, shows the Cu(0) peak for Au-COOH@Cu is centered at 932.6 eV, while for Au-NO 2 @Cu is centered at 932.4 eV, which reveals a 0.2 eV positive shift in Au-COOH@ Cu. This shift indicates a slight increase in the electrostatic attraction of Cu 2p core electrons, leading to a positive shift in the binding energy, which corresponds to increased copper oxidation.…”

“…Most devised methodologies for grafting organic layers or AuNPs on copper metal have employed electrochemical processes for decades. − The electrochemical reduction of aryldiazonium salts on a copper surface to form strongly bonded organic layers has been employed to inhibit corrosion and develop ice-phobic surfaces . Mooste et al reported the electrochemical grafting of anthraquinone diazonium salts on copper electrodes .…”

When ionic liquids meet diazonium salts to generate thin layers of modified surfaces

“…Numerous strategies are reported in the literature and several reviews were devoted to this topic as well as the potential applications of the modified surfaces in various fields including, molecular electronics, energy storage and conversion and sensor devices. [6][7][8][9][10][11] All the described strategies for the immobilization of organic layers share a common principle, thus, the molecule should contain anchoring groups (SH, NH2, Si(OR)3, COOH, N2 + ..) and the desired functional groups that will be attached to the extreme electrode interface.…”