In Situ Device‐Level TEM Characterization Based on Ultra‐Flexible Multilayer MoS₂ Micro‐Cantilever

Abstract

Current state‐of‐the‐art in situ transmission electron microscopy (TEM) characterization technology has been capable of statically or dynamically nanorobotic manipulating specimens, affording abundant atom‐level material attributes. However, an insurmountable barrier between material attributes investigations and device‐level application explorations exists due to immature in situ TEM manufacturing technology and sufficient external coupled stimulus. These limitations seriously prevent the development of in situ device‐level TEM characterization. Herein, a representative in situ opto‐electromechanical TEM characterization platform is put forward by integrating an ultra‐flexible micro‐cantilever chip with optical, mechanical, and electrical coupling fields for the first time. On this platform, static and dynamic in situ device‐level TEM characterizations are implemented by utilizing molybdenum disulfide (MoS2) nanoflake as channel material. E‐beam modulation behavior in MoS2 transistors is demonstrated at ultra‐high e‐beam acceleration voltage (300 kV), stemming from inelastic scattering electron doping into MoS2 nanoflakes. Moreover, in situ dynamic bending MoS2 nanodevices without/with laser irradiation reveals asymmetric piezoresistive properties based on electromechanical effects and secondary enhanced photocurrent based on opto‐electromechanical coupling effects, accompanied by real‐time monitoring atom‐level characterization. This approach provides a step toward advanced in situ device‐level TEM characterization technology with excellent perception ability and inspires in situ TEM characterization with ultra‐sensitive force feedback and light sensing.

On-Chip Light-Incorporated In Situ Transmission Electron Microscopy of Metal Halide Perovskite Materials

“…Atomic force microscopy (AFM) and synchrotron/laboratory X-ray diffraction are popular methods exploited for studying light responses in MHPs, as these measurements are performed mostly in non-vacuum and open environments where light can be incorporated easily. , Still, AFM and X-ray probes are limited to revealing either morphological or statistical phase information, calling for the use of analytical transmission electron microscopy (TEM). TEM can simultaneously provide both morphological and phase information, and more importantly, unlock an extremely high spatial resolution (from the atomic to nanometer scales). − The recent development of TEM characterization for MHPs has been proven successful with regard to the unprecedented local structure/phase information and insightful knowledge achieved. − Nevertheless, it remains an utmost challenge to incorporate a light component into TEM characterization, which has only been tried in only a handful of studies for non-MHP materials systems. − Generally, commercially available in situ TEM platform setups can provide controls only on temperature, − atmosphere, liquid, , and electrical bias, , restricting the study of any light effects on the transformation and degradation of MHPs. , …”