09:30 〜 09:45
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[7a-A405-3] Highly Luminescent YAP Thin Films as Nanoscale Optical Source for
Ultra-High Resolution Microscopy
キーワード：super-resolution microscopy, nanoimaging, thin-films
1. Introduction
Far-field, as well as near-field approaches of super-resolution microscopy prospered in recent years. However, despite of variety techniques demonstrated nanoscale resolution, none of them are capable for imaging without dyes or label-free.
We have proposed an electron-beam excitation-assisted (EXA) optical microscope, where invasive character of electron irradiation vanished by luminescent film, producing noninvasive optical excitation for high resolution imaging of living cells.
2. YAP films as the nanoscale optical source
EXA microscope consists of inverted scanning electron microscope (SEM) and fluorescent microscope. Electron beam focused on luminescent film into a spot of few nm in diameter excites the nanoscale cathodoluminescence (CL).
We have fabricated thin scintillating films of gadolinium-doped yttrium aluminum perovskite (YAP) that act as a bright nanoscale optical source. Excited by a focused electron beam, YAP film emits tiny CL spot. This optical spot of a few tens nm in diameter generated in YAP thin film in near-field regime. Subsequent rastering over the film with a SEM gives a reconstructive image of the specimen with an ultra-high resolution.
Near-field approach involves the illumination, as well as the distance between optical source and the sample are smaller than the excitation wavelength. The CL light from YAP thin film is scattered in the specimen, collected and detected with a high sensitive photodetector. The near-field illumination makes it possible to achieve ultra-high resolution up to few tens of nanometers.
Because the specimen is located directly on thin film, the surface must be smooth, homogeneous and must emit persistent CL. CL intensity distribution of the YAP film is uniform with a 1.5% deviation, which indicates by normal distribution.
3. Conclusions
YAlO3:Gd3+/LaAlO3 thin films on Si/Si3N4/Y2O3 substrates have been fabricated by radio-frequency magnetron sputtering. We report superior bright and homogeneous ultraviolet (UV) emission with a peak wavelength at 317 nm. CL spectra is characterized by a sharp, intensive peak attributed to Gd3+ 6P7/2-8S7/2 transitions.
YAP thin films are very promising as illuminating source for super-resolution microscopy, such as integrated light-electron microscope in which an inverted high-NA objective lens is positioned inside a SEM (Zonneville et al.); in EXA microscope for biological research and future single molecule detection; and as a free-standing membrane in bionanoreactor for dynamic nanoimaging (Nalan Liv et al.).
Far-field, as well as near-field approaches of super-resolution microscopy prospered in recent years. However, despite of variety techniques demonstrated nanoscale resolution, none of them are capable for imaging without dyes or label-free.
We have proposed an electron-beam excitation-assisted (EXA) optical microscope, where invasive character of electron irradiation vanished by luminescent film, producing noninvasive optical excitation for high resolution imaging of living cells.
2. YAP films as the nanoscale optical source
EXA microscope consists of inverted scanning electron microscope (SEM) and fluorescent microscope. Electron beam focused on luminescent film into a spot of few nm in diameter excites the nanoscale cathodoluminescence (CL).
We have fabricated thin scintillating films of gadolinium-doped yttrium aluminum perovskite (YAP) that act as a bright nanoscale optical source. Excited by a focused electron beam, YAP film emits tiny CL spot. This optical spot of a few tens nm in diameter generated in YAP thin film in near-field regime. Subsequent rastering over the film with a SEM gives a reconstructive image of the specimen with an ultra-high resolution.
Near-field approach involves the illumination, as well as the distance between optical source and the sample are smaller than the excitation wavelength. The CL light from YAP thin film is scattered in the specimen, collected and detected with a high sensitive photodetector. The near-field illumination makes it possible to achieve ultra-high resolution up to few tens of nanometers.
Because the specimen is located directly on thin film, the surface must be smooth, homogeneous and must emit persistent CL. CL intensity distribution of the YAP film is uniform with a 1.5% deviation, which indicates by normal distribution.
3. Conclusions
YAlO3:Gd3+/LaAlO3 thin films on Si/Si3N4/Y2O3 substrates have been fabricated by radio-frequency magnetron sputtering. We report superior bright and homogeneous ultraviolet (UV) emission with a peak wavelength at 317 nm. CL spectra is characterized by a sharp, intensive peak attributed to Gd3+ 6P7/2-8S7/2 transitions.
YAP thin films are very promising as illuminating source for super-resolution microscopy, such as integrated light-electron microscope in which an inverted high-NA objective lens is positioned inside a SEM (Zonneville et al.); in EXA microscope for biological research and future single molecule detection; and as a free-standing membrane in bionanoreactor for dynamic nanoimaging (Nalan Liv et al.).