Tip-enhanced photoluminescence nano-spectroscopy and nano-imaging

• Published in: Nanophotonics (Berlin, Germany) Vol. 9; no. 10; pp. 3089 - 3110
• Main Authors: Lee, Hyeongwoo, Lee, Dong Yun, Kang, Min Gu, Koo, Yeonjeong, Kim, Taehyun, Park, Kyoung-Duck
• Format: Journal Article
• Language: English
• Published: Berlin De Gruyter 02.09.2020; Walter de Gruyter GmbH
• Subjects: Biomedical materials; Far fields; Imaging; low-dimensional quantum materials; Material properties; Optical properties; Photoluminescence; plasmonic tip; Sensitivity; Spatial resolution; Spectroscopy; Spectrum analysis; Spontaneous emission; tip-enhanced photoluminescence (TEPL)
• ISSN: 2192-8606; 2192-8614
• DOI: 10.1515/nanoph-2020-0079

Photoluminescence (PL), a photo-excited spontaneous emission process, provides a wealth of optical and electronic properties of materials, which enable microscopic and spectroscopic imaging, biomedical sensing and diagnosis, and a range of photonic device applications. However, conventional far-field PL measurements have limitations in sensitivity and spatial resolution, especially to investigate single nano-materials or nano-scale dimension of them. In contrast, tip-enhanced photoluminescence (TEPL) nano-spectroscopy provides an extremely high sensitivity with <10 nm spatial resolution, which allows the desired nano-scale characterizations. With outstanding and unique optical properties, low-dimensional quantum materials have recently attracted much attention, and TEPL characterizations, i. e., probing and imaging, and even control at the nano-scale, have been extensively studied. In this review, we discuss the fundamental working mechanism of PL enhancement by plasmonic tip, and then highlight recent advances in TEPL studies for low-dimensional quantum materials. Finally, we discuss several remaining challenges of TEPL nano-spectroscopy and nano-imaging, such as implementation in non-ambient media and in situ environments, limitations in sample structure, and control of near-field polarization, with perspectives of the approach and its applications.