The Center for Nanoscale Science and Technology (CNST) of NIST anticipates that there will be (summer 2016) an opportunity to conduct postdoctoral research on the following topic:
Measuring the chemical composition and the optical properties of materials at the nanoscale with an Atomic Force Microscope
CNST is developing a multifunctional instrument based on the Photothermal Induced Resonance (PTIR) technique that is capable of mapping topological, chemical (infrared), optical (bandgap, defects), thermal, and mechanical properties, all with spatial resolution of 20 nm. PTIR relies on a pulsed wavelength-tunable laser to illuminate the sample and on an AFM tip as a local detector to measure absorption spectra and maps by transducing the thermal expansion of the sample induced by light absorption. Our instrumentation consists of 2 AFMs coupled with 4 broadly tunable lasers, covering the spectral range from 400 nm to 16.0 μm continuously, thus enabling the acquisition of correlated vibrational and electronic spectra.
This project has two goals:
- Increase the sensitivity and the speed of our PTIR instrument.
- Apply PTIR to characterize nanomaterials and answer outstanding questions in high impact applications, in collaboration with CNST users.
This research opportunity available within a multidisciplinary team in the CNST user facility (NanoLab) requires an expertise in the development or customization of scanning probe instrumentation. Candidates with a broad and multidisciplinary background are preferred.
A combination of expertise or basic knowledge in some of the following fields is desirable:
- IR spectroscopy
- Solar cells materials
- 2D materials
- Metal-Organic framework
For reference, below you find a list of recent representative PTIR publications from the Centrone group:
- Chloride Incorporation Process in CH3NH3PbI3–xClx Perovskites via Nanoscale Bandgap Maps
Nano Letters, 15 , 8114-38121 (2015) doi:10.1021/acs.nanolett.5b03556
- Photovoltaic Switching Mechanism in Lateral Structure Hybrid Perovskite Solar Cells
Advanced energy materials, 5, 1500615 (2015) doi:10.1002/aenm.201500615
- Assessing chemical heterogeneity at the nanoscale in mixed-ligand metal–organic frameworks with the PTIR technique
Angewandte Chemie International Edition, 53, 2852–2856 (2014) doi:10.1002/anie.201309295
- Nanoscale Imaging of Plasmonic Hot Spots and Dark Modes with the Photothermal-Induced Resonance Technique
Nano Letters, 13 (7), 3218–3224 (2013) doi:10.1021/nl401284m
NIST, Center for Nanoscale Science and Technology, Gaithersburg, 100 Bureau Drive, MD 20899, USA