Keywords: electron microscope TEM、SEM、 Ball aberration correction, in-situ imaging

Electron microscopy (EM) uses electron beams instead of visible light to achieve nanoscale resolution imaging. Its core branches include transmission electron microscopy (TEM) and scanning electron microscopy (SEM), which are widely used in materials science, life sciences, and semiconductor industry.

1、 TEM: From Structural Analysis to Atomic Imaging

TEM penetrates ultra-thin samples through electron beams, forming transmission, scattering, and diffraction signals. Its resolution can reach 0.2 nanometers, suitable for crystal structure analysis and atomic level imaging. For example, in semiconductor material research, HRTEM can analyze lattice defects and interface structures, providing a basis for optimizing device performance.

The introduction of aberration correction technology has increased the TEM resolution to sub angstroms. For example, through the Cs corrector, scientists directly observed the arrangement of individual atoms on metal surfaces for the first time, promoting the development of surface science.

2、 SEM: From Surface Morphology to Composition Analysis

SEM scans the surface of the sample with an electron beam to detect secondary or backscattered electron signals. Its core advantages include a large depth of field and high resolution. For example, in metal fracture analysis, SEM can clearly display the dimple structure; In the failure analysis of semiconductor devices, SEM can locate the source of contaminating elements.

SEM combined with energy dispersive spectroscopy (EDS) can achieve micro elemental analysis. For example, in geological samples, EDS can quickly identify mineral composition; In battery material research, EDS can analyze the elemental distribution on the electrode surface and reveal the mechanism of capacity decay.

3、 In situ electron microscopy: real-time observation of dynamic processes

In situ TEM and SEM techniques integrate heating, stretching, electric field and other devices to observe the phase transition behavior of materials in real-time under extreme conditions. For example, in lithium-ion battery research, in-situ TEM can observe the structural evolution of electrode materials during charge and discharge processes; In material mechanics testing, in-situ SEM can record the crack propagation path, providing a basis for material design.

4、 Technological Challenges and Future Directions

The current challenges include complex sample preparation, electron beam damage, and data analysis complexity. Future trends include:

Low temperature electron microscope: Observing biological samples at liquid nitrogen temperature to reduce radiation damage.

Machine learning assisted analysis: Automatically identify defect types and sizes to improve detection efficiency.

Multimodal imaging system: integrates electronic, optical, and mechanical signals to achieve multidimensional representation.