Koo Seunghoe, Park Jaehee, Kim Kyeongtae
Department of Mechanical Engineering, Incheon National University, Incheon 22012, Korea.
Nanomaterials (Basel). 2022 Apr 27;12(9):1479. doi: 10.3390/nano12091479.
The thermophysical properties at the nanoscale are key characteristics that determine the operation of nanoscale devices. Additionally, it is important to measure and verify the thermal transfer characteristics with a few nanometer or atomic-scale resolutions, as the nanomaterial research field has expanded with respect to the development of molecular and atomic-scale devices. Scanning thermal microscopy (SThM) is a well-known method for measuring the thermal transfer phenomena with the highest spatial resolution. However, considering the rapid development of atomic materials, the development of an ultra-sensitive SThM for measuring pico-watt (pW) level heat transfer is essential. In this study, to measure molecular- and atomic-scale phenomena, a pico-watt scanning thermal microscopy (pW-SThM) equipped with a calorimeter capable of measuring heat at the pW level was developed. The heat resolution of the pW-SThM was verified through an evaluation experiment, and it was confirmed that the temperature of the metal line heater sample could be quantitatively measured by using the pW-SThM. Finally, we demonstrated that pW-SThM detects ultra-small differences of local heat transfer that may arise due to differences in van der Waals interactions between the graphene sheets in highly ordered pyrolytic graphite. The pW-SThM probe is expected to significantly contribute to the discovery of new heat and energy transfer phenomena in nanodevices and two-dimensional materials that have been inaccessible through experiments.
纳米尺度的热物理性质是决定纳米器件运行的关键特性。此外，随着分子和原子尺度器件的发展，纳米材料研究领域不断扩大，以几纳米或原子尺度分辨率测量和验证热传递特性变得很重要。扫描热显微镜（SThM）是一种用于测量具有最高空间分辨率的热传递现象的知名方法。然而，考虑到原子材料的快速发展，开发一种用于测量皮瓦（pW）级热传递的超灵敏SThM至关重要。在本研究中，为了测量分子和原子尺度的现象，开发了一种配备能够测量皮瓦级热量的量热计的皮瓦扫描热显微镜（pW-SThM）。通过评估实验验证了pW-SThM的热分辨率，并证实了使用pW-SThM可以定量测量金属线加热器样品的温度。最后，我们证明了pW-SThM能够检测到由于高度有序热解石墨中石墨烯片之间范德华相互作用的差异而可能出现的局部热传递的超小差异。预计pW-SThM探针将对发现纳米器件和二维材料中通过实验无法实现的新的热和能量传递现象做出重大贡献。
