High-resolution transmission electron microscopy (HRTEM) is an important approach to analyzing material structures. However, in reality, preparing a sufficiently thin sample for use in HRTEM, based on which images could be interpreted by weak phase object approximation theory, is difficult. During the imaging process, the thickness of the sample has two primary effects—a dynamical effect and a non-linear effect. Both are reviewed in this paper. Considering only the dynamical effect, the Bloch wave method and multislice theory have been proposed to understand the relationship between sample thickness and imaging. These methods exhibit high accuracy but high complexity as well. Sacrificing accuracy, pseudo-weak phase object approximation (PWPOA) theory can provide clues to the relationship in reciprocal space with greater simplicity. Meanwhile, in real space, channeling theory describes the dynamical effect with sufficient accuracy, and with the 1s state approximation, i.e., for a certain range of thicknesses, it provides a physical image and simplified expression with which to describe the relationship between the exit wave and sample thickness. As for the non-linear effect, a method of separating linear and non-linear information using a combination of transmission cross-coefficient theory and PWPOA theory was recently proposed. The variation of non-linear and linear imaging with sample thickness has also been discussed. A deep understanding has been acquired regarding the effects of the sample thickness, but a complete understanding of the HRTEM imaging process for thick samples has remained elusive. This understanding is crucial to the retrieval of structure from HRTEM images.

高分辨率透射电子显微镜（HRTEM）是分析材料结构的重要方法。然而，实际上，很难制备出足够薄的样品用于HRTEM，以薄弱的物体近似理论为基础来解释图像。在成像过程中，样品的厚度具有两个主要作用-动力学作用和非线性作用。两者都在本文中进行了回顾。仅考虑动力学效应，提出了布洛赫波法和多层理论来理解样品厚度和成像之间的关系。这些方法显示出很高的准确性，但是也很复杂。伪弱相位对象逼近（PWPOA）理论可提高准确性，可以为互易空间中的关系提供线索，并且更为简单。同时，在实际空间中，通道理论以足够的精度描述了动力学效应，并以1s状态近似表示，即对于一定范围的厚度，它提供了物理图像和简化的表达式，用以描述出射波与样本之间的关系。厚度。关于非线性效应，最近提出了一种将传输交叉系数理论和PWPOA理论相结合的分离线性信息和非线性信息的方法。还讨论了非线性和线性成像随样品厚度的变化。对于样品厚度的影响已获得了深刻的了解，但是对于厚样品的HRTEM成像过程的完整了解仍然难以捉摸。这种理解对于从HRTEM图像中检索结构至关重要。