| Raw and Pixon reconstructed Z-Contrast Scanning Transmission Electron Micrograph (Z-STEM) of a Cd Se (cadmium selenide) nonocrystal embedded in MEH-PPV polymer. The image was obtained on the VG HB603 STEM in the Electron Microscopy Group, Oakridge National Lab., Stephen Pennycook, PI. The nanocrystal composite sample was prepared in the group of Prof. Sandy Rosenthal, Vanderbilt University. Tadd Kippeny: noncrystal synthesis; Meg Erwin: polymer synthesis; Peter Nellist: assistance with STEM operation; Andreas Kadavanich: fabrication of the composite and microscopy. The bright objects are Cd atoms. The darker objects adjacent to the Cd atoms are the Se atoms, roughly 1.5 Angstoms away. CdSe pairs are separated by approximately 3.6 Angstroms. The scanning beam PSF had a FWHM of 1.5 Angstroms and was sampled with approximately 11 to 12 pixels across the FWHM. |
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