Synthesis of Highly Oriented Graphite Films with a Low Wrinkle Density and Near-Millimeter-Scale Lateral Grains

Abstract

Principal defects found in graphite films include grain boundaries and wrinkles. These defects are well known to have detrimental effects on properties such as thermal and electrical conductivities as well as mechanical properties. With a two-fold objective of synthesizing graphite films with large single crystal grains and no wrinkles, we have developed a relatively low temperature (< 1150 °C) process that involves the precipitation of graphite films from nickel-carbon solid solutions followed by in-situ etching of the nickel foil substrates with anhydrous chlorine gas to obtain near wrinkle free continuous graphite films. The size (La) distribution of lateral grains (or single crystal regions) in these highly oriented graphite films has been found to be asymmetric with the largest grains about 0.9 mm in diameter, as determined by electron backscatter diffraction (EBSD). Thus, the growth of large area graphite films with grains much larger than those reported for highly oriented pyrolytic graphite (HOPG, ~20-30 µm), and with a low density of wrinkles, as in the case of HOPG, but prepared at much lower temperatures, is reported here.

Strained Epitaxy of Monolayer Transition Metal Dichalcogenides for Wrinkle Arrays

“…35,37,38 However, the single-crystal quartz, which possesses anisotropic TECs at the m-plane, offers anisotropic thermal strain within 2D materials directly grown on it. As shown in Figure 1e, the (0001) plane of WS 2 is epitaxially grown on m-plane quartz, which includes the quartz z-axis (along [0001] quartz ) and y-axis (along with [11][12][13][14][15][16][17][18][19][20] quartz ). When viewing from the quartz y-axis (Figure 1f), the substrate has a very close TEC with that of TMDCs (α sub ≈ α 2D ) along the z-axis, 39 indicating a quasi-strain-free process during the temperature variation.…”

Semi-transparent graphite films growth on Ni and their double-sided polymer-free transfer

“…5 g shows two superimposed hexagonal patterns rotated by 20°. The two or three sets of hexagonal patterns in the FLG areas could have originated from the three in-plane or out-of-plane graphene layers rotated with respect to each other 33 . By contrast, the electron diffraction patterns of Fig.…”

“…Mater. 2020 33 GF Hot wall CVD Ni film (0.475) /Spinel 850–1,035 15; 90 66 22–2,254 0.01 Polymer assisted; NM NM Growth of single crystal graphite domains on Ni film on spinel substrate, GF grain size 10—100 µm Limited area single crystal domains, long process time, surface defects present Lu Cryst. Eng.…”

“…Catalytic chemical vapour deposition (CVD) is a known method to produce graphene and ultrathin graphite films (< 10 nm) with high structural quality and at reasonable costs [21][22][23][24][25][26][27] . However, in comparison with the graphene and ultrathin-graphite film growth 28 , the large-area growth and/or applications of NGF using CVD remain less explored 11,13,[29][30][31][32][33] .…”

Scalable crystalline porous membranes: current state and perspectives

“…6a-b). 76,[146][147][148] The MOFs were covalently bonded to polymers by photopolymerization, 76,92 thiolene click, 149 atom transfer radical polymerization, 150 or ring opening metathesis polymerization. 151 The obtained membrane (mostly mixed matrix membranes: MMMs) possessed improved separation performance for gas and liquid mixtures, especially improved permeability due to the high amount of MOFs in the composite materials.…”