Specimen preparation methods for elemental characterisation of grain boundaries and isolated dislocations in multicrystalline silicon using atom probe tomography
Specimen preparation methods for elemental characterisation of grain boundaries and isolated dislocations in multicrystalline silicon using atom probe tomography
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DOI：
10.1016/j.matchar.2017.07.038
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发表时间：
2017-09
影响因子：
4.7
通讯作者：
C. Lotharukpong;D. Tweddle;Tomas L Martin;M. Wu;C. Grovenor;M. Moody;P. Wilshaw
中科院分区：
文献类型：
--
作者：
C. Lotharukpong;D. Tweddle;Tomas L Martin;M. Wu;C. Grovenor;M. Moody;P. Wilshaw
多晶硅(MC-Si)是一种成本低廉的太阳能光伏器件的原料，但存在缺陷和杂质的限制。对分离到纳米级位错和晶界的杂质进行成像是一项挑战，几乎没有材料表征技术可以做到这一点。原子探针层析成像(APT)是一种三维飞行时间显微技术，可以在原子尺度上成像元素的分布，然而使用APT时最具挑战性的因素之一是针对特定感兴趣区域的样品制备的复杂性。在双FIB/SEM系统中发展了原子探针样品制备方法，使得能够选择特定的扩展缺陷，如孤立的位错或晶界的一段，用于APT分析。用这种方法从MC-Si样品中的孤立位错和晶界制备了APT样品。互补的透射电子显微镜图像证实了两个样品中缺陷的存在，而APT分析也揭示了杂质对缺陷的偏析。
Multicrystalline silicon (mc-Si) is a cost effective feedstock for solar photovoltaic devices but is limited by the presence of defects and impurities. Imaging impurities segregated to nanometre-scale dislocations and grain boundaries is a challenge that few materials characterisation techniques can achieve. Atom Probe Tomography (APT) is a 3-dimensional time-of-flight microscopy technique that can image the distribution of elements at the atomic scale, however one of the most challenging factors when using APT is the complexity of specimen preparation for specific regions of interest. Atom probe specimen preparation methods have been developed in a dual FIB/SEM system that enable a specific extended defect such as an isolated dislocation or a section of a grain boundary to be selected for APT analysis. The methods were used to fabricate APT specimens from an isolated dislocation and a grain boundary in mc-Si samples. Complementary TEM images confirm the presence of the defects in both specimens, whilst APT analyses also reveal segregation of impurities to the defects.