In-situ TEM Holder for Ultrafast, Multimodal Imaging

Many energy conversion and transfer processes critically depend on the material nanostructure details and its response to external excitation fields Surface and volume defect formation and migration have a profound impact on the opto-electro-thermo-mechanical properties of materials Understanding these processes requires a unique combination of advanced atomic-scale imaging with controlled nanoscale excitation and quantitative probing of fundamental processes The proposed innovation is focused on a method for simultaneous nanoscale multimodal imaging of energy conversion/transfer processes by integrating tip-based pulsed laser radiation sources within a transmission electron microscope (TEM) Nanoscale confinement of radiation fields of enhanced intensity underneath a tip-based probe enables unambiguous and direct in situ interrogation of the nanostructural effects on the material properties In this project, an apparatus combining nanoscale laser excitation and optical signal collection (photoluminescence (PL), time- resolved photoluminescence (TRPL) and Raman spectroscopy) will be designed specifically for integration into a TEM holder and tested First, tapered fiber and near-field probe tips will be de- signed and fabricated for excitation of the optical response of the specimen with nanoscale spatial resolution Second, efficient optical signal collection mechanisms from the excited target will be developed Third, nanoscale PL, TRPL and Raman signal collection will be demonstrated and validated via detailed ex situ TEM experiments and analytical diagnostics The outcome of this project will enable a widespread adoption of unique facility for the in situ direct correlation of optical spectroscopy with atomic level imaging This entirely new capability will undoubtedly have a profound impact to the fields of Materials Science and Manufacturing The users of the proposed approach can embark on a host of fundamental studies on the true nanoscale interaction of photons with materials that are impossible to conduct by the presently available instrumentation For instance, the in situ laser probe will give a user a front row seat to examining fundamental features of energy conversion and transfer processes