With the rapid development of novel functional materials (such as molecular sieves, metal–organic frameworks, and biomimetic materials), high-resolution microstructural characterization of electron beam-sensitive materials faces severe challenges. Conventional transmission electron microscopy (TEM) techniques often induce severe radiation damage to these materials under high-energy electron beam irradiation, resulting in crystalline-to-amorphous phase transition. This can significantly impair atomic-resolution imaging and hinder the study of structure–property relationships. Addressing the fundamental challenge of minimizing beam damage while maintaining high-resolution imaging with excellent signal-to-noise ratio has become a scientific priority for the structural and chemical analysis of electron beam-sensitive materials using electron microscopy. Thus, this study aims to establish a cost-effective, low-dose technique for characterizing materials using conventional TEM through systematic optimization of electron-optical parameters and imaging conditions.

The investigations were conducted using a field-emission TEM (JEOL JEM-F200, Japan) equipped with a bottom-mounted CMOS camera (XAROSA-EMSIS, German). Stepwise univariate analysis was employed to investigate the key parameters governing the electron dose, including the acceleration voltage, electrostatic lens potentials, condenser lens current, C2 aperture size, and irradiation time. The beam current was quantitatively monitored in situ using an external picoammeter connected to the TEM’s Faraday cup. All measurement data were converted to the electron dose rate (e/Ų·s) to enable quantitative comparison for isolating parameter-specific effects and synergistic mechanisms. To improve the performance of the system for low-dose imaging, comprehensive technical optimizations were implemented, including precision TEM alignment (gun tilt/shift, condenser lens calibration, and stigmatism correction), objective lens aberration correction under high-magnification, camera exposure parameter tuning and energy-dispersive spectrometer efficiency improvements.

A complete low-dose TEM characterization system was successfully implemented through hierarchical parameter optimization. First, moderately reducing the acceleration voltage can significantly decrease the initial dose. Second, adjusting the current of the condenser lens (beam spot size reduction) and controlling the irradiation time are simple approaches for effectively suppressing electron beam damage. Finally, the electrostatic lens voltage and C2 aperture size should be adjusted according to the sample’s characteristics and characterization requirements. Multi-parameter synergistic regulation can achieve superior dose reduction compared to single-parameter adjustments. Through systematic optimization of electron-optical parameters and imaging conditions, high-resolution microscopic imaging with a high signal-to-noise ratio was achieved under low-dose conditions using conventional TEM. The developed method can successfully resolve the technical challenge of balancing the resolution and signal-to-noise ratio in traditional low-dose modes, thereby providing a reliable solution for atomic-scale structural analysis of electron beam-sensitive materials.

A cost-effective and highly efficient low-dose TEM methodology was developed through an innovative “methodology-over-hardware” approach, overcoming the technical limitations of conventional TEM in characterizing electron beam-sensitive materials. By establishing a dynamic equilibrium model between dose control and image quality, ordinary TEM can achieve low-damage characterization capabilities comparable to those of cryo-TEM without requiring additional hardware investments. This technology can provide customized low-dose testing solutions for various sensitive materials, significantly enhancing the efficiency of equipment and service capabilities of public testing platforms. The developed approach possesses extensive practical value and promotion prospects, offering a new paradigm for precise microscopic analysis of beam-sensitive materials.