标题： 通过聚焦电子束辐照在不同气体下聚苯乙烯增强的图案化荧光 显示英文标题

标题： Enhanced Patterned Fluorescence from Polystyrene through Focused Electron Beam Irradiation under Various Gases

摘要： 我们报告了一种通过电子束在气态环境中曝光来调节和增强辐照聚苯乙烯荧光的新方法。 我们描述了电子剂量和环境气体对绝缘和导电基底上辐照PS薄膜的光致发光光谱和产率的影响。 PS薄膜在环境扫描电子显微镜中使用20 keV电子束、从高真空到3毫巴的环境气体压力以及1.8至45 mC cm⁻²的电子剂量进行了曝光。 辐照的PS薄膜使用共聚焦显微镜、TEM、EDS和FTIR光谱进行了表征。 从使用共焦显微镜收集的发射光谱中发现，发射波长和光子产率可以通过剂量和气体压力进行调节。 随着压力增加，发射波长向蓝光方向移动；随着剂量增加，发射波长向红光方向移动，从而实现了451至544纳米的整体调谐范围。 在氦气环境下，与高真空相比，蓝宝石基底上的PL强度显著增强了高达18倍。 总体而言，在氩气下，钠石灰玻璃基底上观察到了最高的PL产率。 此外，导电基底上的光子产率明显小于绝缘基底上的产率。 TEM图像显示，电子束辐照的PS本质上是非晶态的，而EDS元素映射未发现薄膜氧化的迹象。 FTIR光谱表明，在气态环境中，芳香和脂肪族C-H拉伸的衰减相比于高真空暴露有所减少；在所有情况下，与苯环相关的特征均得以保留。 PS中的荧光团局部电子束合成可以通过剂量和环境气体压力进行控制。 该技术可能使新的光子学方法成为可能，在这些方法中，可以通过电子束图案化局部引入具有可调发射特性的荧光团。 显示英文摘要

摘要： We report on a novel method for tuning and enhancing fluorescence from irradiated polystyrene through electron-beam exposure in gaseous environments. We describe the effect of electron dose and ambient gas on the photoluminescence spectra and yield of irradiated PS films on insulating and conductive substrates. PS films were exposed in an environmental scanning electron microscope using a 20 keV electron beam, ambient gas pressures from high vacuum to 3 mbar, and electron doses from 1.8 to 45 mC cm-2. Irradiated PS films were characterized using confocal microscopy, TEM, EDS and FTIR spectroscopy. From emission spectra collected using confocal microscopy we found that the emission wavelength and photon yield of the irradiated film can be tuned by both dose and gas pressure. The emission wavelength blue-shifts with increasing pressure and red-shifts with increasing dose enabling an overall tuning range of 451 - 544 nm. Significant enhancement in the PL intensity, up to 18 times on sapphire substrates under helium when compared to high vacuum, are observed. Overall, the highest PL yield is observed on soda lime glass substrates under argon. Also, the photon-yield on conductive substrates is significantly smaller than that yield from insulating substrates. TEM images revealed e-beam irradiated PS is amorphous in nature and elemental mapping EDS revealed no signs of film oxidation. FTIR spectroscopy revealed that under gaseous environments the decay of aromatic and aliphatic C-H stretches is reduced compared to the high vacuum exposure; in all cases, features associated with the phenyl rings are preserved. Localized e-beam synthesis of fluorophores in PS can be controlled by both dose and by ambient gas pressure. This technique could enable new approaches to photonics where fluorophores with tunable emission properties can be locally introduced by e-beam patterning.