in-situ Electrical & Optical TEM Platform
The ability to observe the dynamic behavior of these materials under real working conditions using advanced TEM technologies would provide an in-depth understanding of their working mechanisms, enabling further improvement of their properties. In this work, we designed a microelectromechanical-system-chip-based system to illuminate a sample inside a transmission electron microscope. This system allows simultaneous in situ optical and electrical measurements, which are crucial for optoelectronic semiconductor characterization[Ultramicroscopy,194, 57-63 (2018)].
In-situ TEM Study of Nano-ionic Resistive Memories (Re-RAM)
There is a niche application involving ion transport in solid state which manifested itself as non-volatile memory namely memristor. Van der Waals heterostructure based on layered 2D materials offers unprecedented opportunities to create materials with atomic precision by meticulous design. By combining superior properties of each component, such heterostructure also provides possible solutions to address various challenges of the electronic devices, especially those with vertical multilayered structures. Here, we report the realization of ultra-robust memristors for the first time based on vdW heterostructure of fully layered 2D materials (graphene/MoS2-xOx/graphene).By combining in-situ high-resolution TEM and STEM studies, a well-defined conduction channel and a switching mechanism based on the migration of oxygen ions were revealed [Nature Electronics,1, 130-136 (2018)].
In-situ TEM Study of Nano-battery
Structure changes and phase transitions of electrode materials during electrochemical cycling are crucial factors which determine the battery performance. Isolation of electrode materials from the electrochemical system in ex-situ experiments often causes changes in structure or chemical composition, that is, some intermediate information may be missed. Electrochemical reactions occur in non-equilibrium state and localization could be detected by in situ electrical biasing experiments in TEM with high spatial and temporal resolution to reveal the dynamic transformation mechanism of electrode materials. In situ TEM provides direct, real-time lithiation/delithiation prospects at the atomic scale to help understanding reaction kinetics in electrochemical process.