王子熙^1，2， 吴丽梅¹， 李硕²， 张鼎昀²

1.沈阳建筑大学 材料科学与工程学院， 辽宁 沈阳 110168；

2.中国计量科学研究院前沿计量科学中心， 国家市场监督管理总局技术创新中心（石墨烯计量与标准技术）， 北京 100029

引用格式：

王子熙， 吴丽梅， 李硕， 等. 激光闪射法测量石墨烯薄膜热扩散系数的影响因素［J］. 中国粉体技术， 2026， 32（3）： 1-15.

WANG Zixi， WU Limei， LI Shuo， et al. Influencing factors of thermal diffusivity of graphene films measured by laser flash method［J］. China Powder Science and Technology， 2026， 32（3）： 1-15.

DOI：10.13732/j.issn.1008-5548.2026.03.016

收稿日期： 2025-04-14， 修回日期： 2025-09-09，上线日期： 2025-11-20。

基金项目： 国家重点研发计划项目，编号：2022YFF0608604；国家市场监督管理总局技术创新中心（石墨烯计量与标准技术）开放课题，编号：AKYKF2419。

第一作者： 王子熙（2001—），男，硕士生，研究方向为材料热物性计量。E-mail：1042482345@qq.com。

通信作者： 李硕（1987—），男，副研究员，博士，硕士生导师，研究方向为材料热物性计量。E-mail：lishuo@nim.ac.cn。

摘要： 【目的】 对激光闪射法测量石墨烯薄膜面内热扩散系数的主要影响因素进行研究，建立稳定可重复的测量方法。【方法】 采用拉曼光谱仪、X射线衍射仪、透射电镜和原子力显微镜等，对石墨烯薄膜原料氧化石墨烯粉体进行表征测试，采用拉曼光谱仪、扫描电子显微镜、原子力显微镜和X射线光电子能谱等，对石墨烯薄膜进行表征，分别探讨干燥状态、石墨涂层、平整度和脉冲条件等因素对石墨烯薄膜热扩散系数的影响。【结果】 氧化石墨烯粉体具有典型的特征拉曼峰D峰和G峰。透射电镜图显示石墨烯褶皱较少，但重叠比较显著，粉体的厚度平均值约为1.2 nm；石墨烯薄膜为多层结构，样品结构完整、碳晶格中基本无缺陷且杂质较少，薄膜平均厚度约为87 μm，表面粗糙度为27~117 nm，薄膜表面较平整；薄膜中C元素原子分数约为97.45%，主要杂质为Si元素，样品的石墨化程度较高。【结论】 石墨烯薄膜的含水量显著影响其导热性能；改进的石墨层喷涂方式保证样品的红外发射率，减小涂层与薄膜表面的接触热阻；将石墨烯薄膜稳定负载于金属圆环垫片上，保证样品的平整稳定，能显著减小低热扩散系数测量结果的标准偏差。

关键词： 激光闪射法； 热扩散系数； 石墨烯薄膜； 石墨涂层； 平整度； 标准物质

Abstract

Objective The laser flash method （LFA） is a non-contact， transient technique for measuring the thermal diffusivity of materials. It offers several advantages such as fast measurement， a wide applicable range， and the ability to test small samples. In recent years， with the rapid development of laser technology， temperature detection， and data processing， LFA has been increasingly applied to measure the in-plane thermal diffusivity of two-dimensional （2D） materials. However， for flexible graphene films with micrometer-scale thickness， challenges such as poor measurement repeatability and difficulties in comparing results still exist. To establish a reliable LFA for measuring the in-plane thermal diffusivity of graphene films， this study analyzes the main factors affecting the measurement results and achieves a stable and repeatable approach for obtaining accurate thermal diffusivity.

Methods Raman spectroscopy， X-ray diffraction （XRD）， transmission electron microscopy （TEM）， and atomic force microscopy （AFM） were used to characterize the graphene oxide powder， which was used as the raw material for preparing graphene films. The graphene films were further characterized using Raman spectroscopy， scanning electron microscopy （SEM）， AFM， and X-ray photoelectron spectroscopy （XPS）. The effects of drying state， graphite coating， surface flatness， and laser pulse conditions on thermal diffusivity of graphene films were investigated. In LFA，the sample surface was heated by a pulse laser，and an infrared detector was used to monitor the temperature response signals on the back or side of the sample over time. As a non-contact technique， it effectively eliminated thermal contact resistance and improved measurement accuracy. There were three commonly used measurement models for LFA：the vertical model， the in-plane model， and the laminate model. In this study， the in-plane model was used for measurements. Due to the high thermal diffusivity of graphene films and their highly reflective surfaces，accurate measurements remain challenging. Therefore， suitable experimental conditions and optimized pretreatment methods were developed to enhance the accuracy of the measurement results.

Results and discussion The results showed that the graphene oxide powder exhibited typical D and G peaks in its Raman spectrum. TEM images revealed that the graphene had minimal wrinkles but significant overlapping layers， with an average thickness of approximately 1.2 nm. The resulting graphene film exhibited a multi-layer structure with an intact carbon lattice， virtually no defects， and minimal impurities. The average thickness of the film was approximately 87 μm， and its surface roughness ranged from approximately 27 nm to 117 nm， indicating a relatively smooth surface. The carbon content of the film was approximately 97.45%， the main impurity was Si， and the degree of graphitization of the sample was high. The moisture content of the graphene film significantly affected its thermal conductivity. The optimized pulse parameters for the 80 μm-thick graphene film used in LFA were as follows： a pulse voltage of 240~260 V， a pulse width of 30~100 μs，and a signal intensity of 3~7 V.Meanwhile，the data fitting model required corrections for finite pulse time and heat loss. Compared with the traditional spraying method，the test curve fitting was significantly improved by spraying the graphite layer only in the laser irradiation and infrared detection areas.After loading onto a metal ring，the average standard deviation of repeated thermal diffusivity measurements was reduced by approximately 50%.

Conclusions This paper summarizes the measurement principle of LFA and its application to determining the thermal diffusivity of 2D materials. A stable and reliable method for measuring in-plane thermal diffusivity of 80 μm graphene films is established with the following key steps： 1） The film should be fully dried before testing； 2） Applying the graphite layer only in the laser irradiation and infrared detection areas ensures sufficient infrared emissivity and reduces the contact resistance between the graphite coating and the graphene film surface； 3） To ensure film surface flatness， the graphene films should be stably loaded onto a metal ring gasket； and 4） The optimized pulse parameters for LFA are a pulse voltage of 240~260 V， a pulse width of 30~100 μs， and a signal intensity of 3~7 V. In addition， the data fitting model requires finite pulse time and heat loss corrections. By applying the optimized in-plane thermal diffusivity measurement method， the 80 μm graphene films successfully passed the uniformity and stability tests， laying a foundation for the development of reference materials.

Keywords： laser flash method； thermal diffusivity； grapheme film； graphite coating； flatness； reference material

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