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

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.

Automated summary

The current state-of-the-art in situ transmission electron microscopy (TEM) characterization technology can manipulate specimens at the nanoscale and provide atom-level material attributes. However, there is a barrier between material attributes investigations and device-level application explorations due to immature in situ TEM manufacturing technology and sufficient external stimuli. This study proposes an in situ opto-electromechanical TEM characterization platform by integrating an ultra-flexible micro-cantilever chip with optical, mechanical, and electrical coupling fields. The platform enables static and dynamic in situ device-level TEM characterizations using molybdenum disulfide (MoS2) as the channel material. The experiments demonstrate electron-beam modulation behavior and bending of MoS2 nanodevices, revealing piezoresistive and opto-electromechanical coupling properties. Real-time atom-level characterization is achieved using this approach, providing a step towards advanced in situ device-level TEM characterization technology.