The microscopic morphology and structural composition of graphene heat dissipation films are closely related to its macroscopic properties such as mechanical properties, thermal conductivity, and electrical conductivity. For guiding the structural design optimization and performing regulation of graphene heat dissipation films, the intrinsic correlation between multi-dimensional structures and properties was explored through comparing the structure-performance relationships of four different types of graphene heat dissipation films. A combination of advanced characterization techniques and performance testing instruments was adopted to systematically investigate the structure and performance of the samples.
For the characterization of microscopic morphology and structural composition, scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were employed. Meanwhile, a laser thermal conductivity meter, universal material testing machine, film square resistance tester, and differential scanning calorimeter were used to test the thermal conductivity, mechanical properties, electrical properties, and thermal stability of the graphene heat dissipation films, respectively. On this basis, the intrinsic correlation between the performance and structural characteristics of the films was analyzed in depth.
The characterization results of microscopic morphology via SEM and AFM show that pore content and compactness are key factors affecting the comprehensive performance of graphene heat dissipation films. Specifically, fewer internal pores and good overall compactness are conducive to the formation of continuous and unobstructed thermal and electrical conduction pathways in the films. This not only reduces the transmission resistance of heat and electrons but also enhances the structural integrity of the films, enabling them to resist external deformation and maintain excellent mechanical properties under service conditions. In contrast, obvious wrinkles on the film surface and voids between graphene layers will break the continuity of conduction pathways, cause scattering of phonons and electrons, and thus significantly reduce the thermal conductivity of the films, even affecting their mechanical stability.
The analysis of structural composition by Raman, XRD, and XPS demonstrates that the graphitization and chemical composition of graphene have a significant impact on the conduction performance of the films. During the preparation process of graphene heat dissipation films, carbon atoms on the graphene basal plane undergo ordered rearrangement under the action of process conditions such as temperature and pressure, triggering a distinct graphitization phenomenon and forming a regular graphite-like crystal structure. Moreover, fewer structural defects and lower oxygen content can minimize phonon scattering during transmission and reduce the hindrance of oxygen-containing functional groups to conduction. Additionally, it is confirmed that an increase in the carbon-oxygen ratio (C/O) contributes to improving the thermal conductivity of graphene heat dissipation films, as it reduces oxygen-containing functional groups and promotes graphitization.
Finally, in this research, the effect laws of film thickness and density on their performance are revealed. It is found that the thermal conductivity of graphene heat dissipation films shows a negative correlation with the thickness: as the thickness increases, the number of internal defects and interlayer interfaces increases, enhancing phonon scattering and reducing thermal conduction efficiency. In contrast, density has a positive correlation with thermal conductivity and tensile strength. Higher density means closer stacking of graphene sheets, fewer internal pores, and stronger interlayer interaction, which optimizes conduction pathways and improves structural stability, leading to higher thermal conductivity and greater tensile strength. These results further confirm that there is a profound intrinsic correlation between the performance system of the films (including thermal conductivity, mechanical properties, electrical properties, and thermal stability) and their microscopic morphology and structural composition.
In conclusion, the microscopic morphology and structural characteristics of the composition of graphene heat dissipation films interact and exert a synergistic effect, jointly shaping their macroscopic properties in terms of thermal conductivity, mechanics, and electricity. In this study, the multi-dimensional structure-property correlation of graphene heat dissipation films is clarified, which is of great significance for guiding the structural optimization and performance regulation of such films, and lays a solid foundation for their wide application in thermal management fields such as high-power electronic equipment.
Key words
graphene /
heat dissipation film /
structural characterization /
performance testing /
structure-property correlation
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References
[1] XIONG K, MA C, WANG J T, et al.Highly Thermal Conductive Graphene/Carbon Nanotubes Films with Controllable Thickness as Thermal Management Materials[J]. Ceramics International, 2023, 49(6): 8847-8855.
[2] YANG S J, ZHENG H L, HE P, et al.Ultra-Thick Graphene Films with High Thermal Conductivity through a Non-Stacking Strategy[J]. Small, 2025, 21(12): e2500855.
[3] YAN Q W, ALAM F E, GAO J Y, et al.Soft and Self-Adhesive Thermal Interface Materials Based on Vertically Aligned, Covalently Bonded Graphene Nanowalls for Efficient Microelectronic Cooling[J]. Advanced Functional Materials, 2021, 31(36): 2104062.
[4] HUANG P, LI Y, YANG G, et al.Graphene Film for Thermal Management: A Review[J]. Nano Materials Science, 2021, 3(1): 1-16.
[5] GONG F, LI H, WANG W B, et al.Recent Advances in Graphene-Based Free-Standing Films for Thermal Management: Synthesis, Properties, and Applications[J]. Coatings, 2018, 8(2): 63.
[6] CHEN S J, WANG Q L, ZHANG M M, et al.Scalable Production of Thick Graphene Film for Next Generation Thermal Management Application[J]. Carbon, 2020, 167: 270-277.
[7] SHAHIL K M F, BALANDIN A A. Thermal Properties of Graphene and Multilayer Graphene: Applications in Thermal Interface Materials[J]. Solid State Communications, 2012, 152(15): 1331-1340.
[8] KIM K S, ZHAO Y, JANG H, et al.Large-Scale Pattern Growth of Graphene Films for Stretchable Transparent Electrodes[J]. Nature, 2009, 457(7230): 706-710.
[9] BOLOTIN K I, SIKES K J, JIANG Z, et al.Ultrahigh Electron Mobility in Suspended Graphene[J]. Solid State Communications, 2008, 146(9/10): 351-355.
[10] LEE C, WEI X D, KYSAR J W, et al.Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene[J]. Science, 2008, 321(5887): 385-388.
[11] DAI W, MA T F, YAN Q W, et al.Metal-Level Thermally Conductive yet Soft Graphene Thermal Interface Materials[J]. ACS Nano, 2019, 13(10): 11561-11571.
[12] BALANDIN A A, GHOSH S, BAO W Z, et al.Superior Thermal Conductivity of Single-Layer Graphene[J]. Nano Letters, 2008, 8(3): 902-907.
[13] SHAHIL K M F, BALANDIN A A. Graphene-Multilayer Graphene Nanocomposites as Highly Efficient Thermal Interface Materials[J]. Nano Letters, 2012, 12(2): 861-867.
[14] SHAN B, XIONG Y Z, LI Y H, et al.Sandwich Structured RGO/CNF/RGO Composite Films for Superior Mechanical and Thermally Conductive Properties[J]. Cellulose, 2020, 27(9): 5055-5069.
[15] LI H L, XIAO S N, YU H L, et al.A Review of Graphene-Based Films for Heat Dissipation[J]. New Carbon Materials, 2021, 36(5): 897-908.
[16] LIU H K, LIN Y, LUO S N.Grain Boundary Energy and Grain Size Dependences of Thermal Conductivity of Polycrystalline Graphene[J]. The Journal of Physical Chemistry C, 2014, 118(42): 24797-24802.
[17] RAJASEKARAN G, NARAYANAN P, PARASHAR A.Effect of Point and Line Defects on Mechanical and Thermal Properties of Graphene: A Review[J]. Critical Reviews in Solid State and Materials Sciences, 2016, 41(1): 47-71.
[18] CAI C L, WANG T, QU G W, et al.High Thermal Conductivity of Graphene and Structure Defects: Prospects for Thermal Applications in Graphene Sheets[J]. Chinese Chemical Letters, 2021, 32(4): 1293-1298.
[19] WU T S, XU Y L, WANG H Y, et al.Efficient and Inexpensive Preparation of Graphene Laminated Film with Ultrahigh Thermal Conductivity[J]. Carbon, 2021, 171: 639-645.
[20] LEE W, KIHM K D, KIM H G, et al.In-Plane Thermal Conductivity of Polycrystalline Chemical Vapor Deposition Graphene with Controlled Grain Sizes[J]. Nano Letters, 2017, 17(4): 2361-2366.
[21] WANG N, SAMANI M K, LI H, et al.Tailoring the Thermal and Mechanical Properties of Graphene Film by Structural Engineering[J]. Small, 2018, 14(29): 1801346.
[22] MA T, LIU Z B, WEN J X, et al.Tailoring the Thermal and Electrical Transport Properties of Graphene Films by Grain Size Engineering[J]. Nature Communications, 2017, 8: 14486.
[23] FERRARI A C, MEYER J C, SCARDACI V, et al.Raman Spectrum of Graphene and Graphene Layers[J]. Physical Review Letters, 2006, 97(18): 187401.
[24] LIU J, SUN W T, WEI D /P, et al. Direct Growth of Graphene Nanowalls on the Crystalline Silicon for Solar Cells[J]. Applied Physics Letters, 2015, 106(4): 043904.
[25] GUO S H, CHEN S J, NKANSAH A, et al.Toward Ultrahigh Thermal Conductivity Graphene Films[J]. 2D Materials, 2023, 10(1): 014002.
[26] CAI C L, WANG T, ZHANG Y X, et al.Facile Fabrication of Ultra-Large Graphene Film with High Photothermal Effect and Thermal Conductivity[J]. Applied Surface Science, 2021, 563: 150354.
[27] LI Z M, PENG J, ZHENG K, et al.Facile Synthesis of a Graphene Film with Ultrahigh Thermal Conductivity via a Novel Pressure-Swing Hot-Pressing Method[J]. Industrial & Engineering Chemistry Research, 2024, 63(10): 4442-4450.
Funding
Project of the Guangdong Provincial Administration for Market Regulation (2024CT16); Project of the Guangdong Provincial Administration for Market Regulation (2025CT14); Project of Guangzhou Municipal Administration for Market Regulation (2025KJ12)
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