| 초록 |
In the past two decades, nanomaterials studies have expanded from pure academic research to application studies due to their unique mechanical and electrical properties. These applications include energy conversion, environment protection, pharmaceutics and various display devices used in our daily life. Scanning probe microscopy (SPM) is one of the widely used technologies for nanomaterials studies since its discovery. For example, in graphene, SPM has been used to determine the number of layers and morphological changes under different treatments. The movement towards applications thus leads to new requirements/criteria of measuring properties critical to the said application on a regular basis including mechanical, electrical properties and surface chemistry. However, traditional SPM is unable to quantify these properties with nanometer resolution. In traditional SPM, local contact is neither known nor well controlled, making measurements unrepeatable, which plagues its applications in mechanical and electric properties measurement. In this article, we will report the latest developments in AFM technology in quantitative nano-mechanics, nano-electrical properties and nano-IR spectroscopy. With the invention of Peak Force Tapping and nano dynamic mechanical analysis (nDMA), we achieved quantitative measurement on elastic modulus as well as loss modulus at different frequency to understand viscoelasticity at different length and temporal scale. DatacubeTM is another technique we just developed to achieve comprehensive nanoelectrical characterization, including but not limited to advanced piezo switching spectroscopy, I-V mapping for electronic and electrical property measurement, and C-V mapping for carrier profiling and carrier behavior characterization. By integrating AFM with IR technology, we achieved IR spectroscopy at nanometer spatial resolution in XYZ and mono molecular layer sensitivity. Besides Nano-IR spectroscopy, we also developed scanning near-field optical microscopy to characterize photon propagation and plasmon propagation in 2D materials. In additional to the discussion about the technology developments, we will use extensive application examples to illustrate how these technology developments enable new researches. |
