Thursday, October 19, 2017
Dr. Mohit Tuteja
NIST
2:00 - 3:00pm
SEH, B1220
Abstract
Advancement in Atomic Force Microscopy (AFM) has enabled the development of AFM-based techniques that enable evaluation of a material’s nanoscale properties viz. mechanical, chemical, opto-electronic, and acousto-thermal properties This has revolutionized the ways in which AFM is being used to measure material properties beyond the conventional topography measurement.
In this presentation, firstly, I will discuss modern AFM’s abilities to measure nanoscale (≈ 20 nm – 50 nm) opto-electronic properties of materials. An example will be presented where a combination of Scanning Microwave Impedance Microscopy (SMIM) and Conductive-AFM has been used to study the nanoscale photovoltaic performance of polycrystalline Cadmium Telluride. I will also discuss SMIM’s ability to measure nanoscale charge carrier concentration in semiconductor materials.
Next, I will discuss Photo-Thermal Induced Resonance (PTIR), another emerging AFM-based technique, useful for measuring nanoscale (≈ 20 nm) chemical composition of materials. Here, similarities between a chemical’s FTIR signature and its PTIR response enable the nanoscale chemical composition identification. Lastly, I will talk about the recent attempts to extend PTIR’s operation ability from IR to visible wavelengths, hence enabling PTIR to map nanoscale optical properties of semiconductor materials.
Biography
Mohit Tuteja is a post-doctoral researcher at the National Institute of Standards and Technology in Maryland. He received his M.S. and Ph.D. degrees in Materials Science and Engineering from the University of Illinois at Urbana-Champaign. His research interests lie in the areas of : application of advanced scanning probe microscopy-based techniques to analyze chemical, thermal, optical, and electronic properties of materials; semiconductor electronics; and photovoltaics.