Riesen Nicolas, Priest Craig, Lancaster David G, Badek Kate, Riesen Hans
University of South Australia, STEM, Future Industries Institute, Mawson Lakes, SA 5095, Australia.
Institute for Photonics and Advanced Sensing (IPAS) and School of Physical Sciences, The University of Adelaide, SA 5005, Australia.
Nanoscale. 2023 Mar 9;15(10):4863-4869. doi: 10.1039/d2nr02931f.
Thin films of BaFCl:Sm nanocrystals prepared using a polymer binder were used to create fluorescence images. The phosphor films were exposed to a UV-C mercury lamp light source chromium-coated quartz greyscale masks to create 4 μm resolution greyscale fluorescence images. The mechanism relies on the highly efficient conversion of Sm to Sm ions upon exposure to UV-C light which displays a large linear dynamic range. The red fluorescence around 688 nm of the Sm is then read-out using blue-violet illumination under a laser scanning confocal microscope. The greyscale images with 16 greyscale levels had a resolution equivalent to ∼125 line pairs per mm or ∼6400 dpi. Improvements in the resolution would be possible using collimated UV-C laser exposure of the film or the use of higher resolution photomasks. Ultra-high resolution binary fluorescence images were also created with resolutions down to 2 μm (∼250 line pairs per mm, ∼12 700 dpi). Downstream applications of the technology could include tailored covert or overt anti-counterfeiting labelling.
使用聚合物粘合剂制备的BaFCl:Sm纳米晶体薄膜用于创建荧光图像。磷光体薄膜暴露于涂有铬的石英灰度掩膜的UV-C汞灯光源下，以创建4μm分辨率的灰度荧光图像。其原理依赖于Sm在暴露于UV-C光时高效转化为Sm离子，该过程显示出较大的线性动态范围。然后在激光扫描共聚焦显微镜下使用蓝紫光照明读取Sm在688nm左右的红色荧光。具有16个灰度级的灰度图像分辨率相当于每毫米约125线对或约6400dpi。使用准直UV-C激光曝光薄膜或使用更高分辨率的光掩膜有可能提高分辨率。还创建了分辨率低至2μm（每毫米约250线对，约12700dpi）的超高分辨率二元荧光图像。该技术的下游应用可能包括定制的隐蔽或公开防伪标签。
