December 1 - 6, 2024
Boston, Massachusetts

Event Supporters

2024 MRS Fall Meeting & Exhibit
CH05.13.03

Carbon Contamination Mitigation for STEM Imaging of Chemically Synthesized Beam Sensitive Materials

When and Where

Dec 4, 2024
8:00pm - 10:00pm
Hynes, Level 1, Hall A

Presenter(s)

Co-Author(s)

Pritish Mishra1,Yee Yan Tay1,Kedar Hippalgaonkar1,2

Nanyang Technological University1,Agency for Science, Technology and Research2

Abstract

Pritish Mishra1,Yee Yan Tay1,Kedar Hippalgaonkar1,2

Nanyang Technological University1,Agency for Science, Technology and Research2
Chemically synthesized materials such as colloidal nanoparticles have been studied a lot in the past decade owing to their ease of synthesis and enhanced properties as compared to their bulk counterparts. Halide - perovskite quantum dots (h-PQDs) are one of these widely researched class of materials due to their near unity Photoluminesence Quantum Yield (PLQY). But due to the presence of organic ligands and highly ionic nature of composition, the material faces extreme carbon contamination and radiolysis damage on exposure to electron beam during Scanning Transmission Electron Microscopy (STEM) imaging and analysis. In this work, we build a methodology for atomic resolution imaging and analysis of such materials with high beam dose at room temperature. One section of the sample is exposed to stationary STEM beam which damages the exposed area of the sample while reducing contamination for the immidiately neighbouring area, thereby improving contrast and reducing astigmatism compensation and image aquisition time. The process has been optimized with different beam voltages and calculated dose rates. The resulting images appear noise free and can be analysed without any need for post processing, filters or image treatments. These results show promise in atomic resolution imaging of all chemically synthesized materials without beam damage and contrast reduction due to carbon contamination.

Keywords

crystallographic structure | perovskites | scanning transmission electron microscopy (STEM)

Symposium Organizers

Miaofang Chi, Oak Ridge National Laboratory
Ryo Ishikawa, The University of Tokyo
Robert Klie, University of Illinois at Chicago
Quentin Ramasse, SuperSTEM Laboratory

Symposium Support

Bronze
EKSPLA 
Protochips
Thermo Fisher Scientific, Inc.

Session Chairs

Miaofang Chi
Quentin Ramasse

In this Session