Quantitative scanning transmission electron microscopy (STEM) allows composition determination for nanomaterials at an atomic scale. To improve the accuracy of the results obtained, optimized imaging parameters should be chosen for annular dark field imaging. In a simulation study, we investigate the influence of imaging parameters on the accuracy of the composition determination with the example of ternary III-V semiconductors. It is shown that inner and outer detector angles and semi-convergence angle can be optimized, also in dependence on specimen thickness. Both, a minimum sampling of the image and a minimum electron dose are required. These findings are applied experimentally by using a fast pixelated detector to allow free choice of detector angles.

定量扫描透射电子显微镜 (STEM) 允许在原子尺度上确定纳米材料的成分。为了提高所得结果的准确性，应为环形暗场成像选择优化的成像参数。在模拟研究中，我们以三元 III-V 族半导体为例研究了成像参数对成分确定精度的影响。结果表明，内部和外部探测器角度和半会聚角可以优化，也取决于样品厚度。需要最小的图像采样和最小的电子剂量。这些发现通过使用快速像素化检测器进行实验应用，以允许自由选择检测器角度。