Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan.
ACS Nano. 2013 Jan 22;7(1):465-70. doi: 10.1021/nn304511p. Epub 2012 Dec 26.
Transmission electron microscopy (TEM) is a powerful tool for imaging nanostructures, yet its capability is limited with respect to the imaging of organic materials because of the intrinsic low contrast problem. TEM phase plates have been in development for decades, yet a reliable phase plate technique has not been available because the performance of TEM phase plates deteriorates too quickly. Such an obstacle prohibits in-focus TEM phase imaging to be routinely achievable, thus limiting the technique being used in practical applications. Here we present an on-chip thin film Zernike phase plate which can effectively release charging and allow reliable in-focus TEM images of organic materials with enhanced contrast to be routinely obtained. With this stable system, we were able to characterize many polymer solar cell specimens and consequently identified and verified the existence of an unexpected nanoparticle phase. Furthermore, we were also able to observe the fine structures of an Escherichia coli specimen, without staining, using this on-chip thin film phase plate. Our system, which can be installed on a commercial TEM, opens up exciting possibilities for TEM to characterize organic materials.
透射电子显微镜（TEM）是一种用于成像纳米结构的强大工具，但由于固有的低对比度问题，其对有机材料的成像能力有限。TEM 相衬板已经开发了几十年，但由于 TEM 相衬板的性能恶化得太快，因此仍然没有可靠的相衬板技术。这种障碍阻止了聚焦 TEM 相衬成像的常规实现，从而限制了该技术在实际应用中的使用。在这里，我们提出了一种片上薄膜泽尼克相位板，它可以有效地释放电荷，并允许常规获得增强对比度的有机材料的可靠聚焦 TEM 图像。有了这个稳定的系统，我们能够对许多聚合物太阳能电池样品进行表征，并因此确定和验证了一种意想不到的纳米颗粒相的存在。此外，我们还能够使用这种片上薄膜相衬板观察未经染色的大肠杆菌样品的精细结构。我们的系统可以安装在商用 TEM 上，为 TEM 对有机材料的特性分析开辟了令人兴奋的可能性。
