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[d] Omnidirectional and [e] partial band gaps in a photonic crystal [a-c, perspective and side views] self-assembled into a monoclinic structure from dimer colloidal particles

Dimer- & Spherocylinder Based 3D Photonic Crystals

Particulate 3D thin films were self-organized from asymmetric-lobed dimers and spherocylinders (cylindrical body with hemisphere end caps) using evaporation mediated vertical deposition. Among others, monoclinic crystals of moderate bond-length dimers and spherocylinders were determined from focused ion-beam sections as well as rotator solids (rotationally random ‘plastic crystal’) for short-bond length dimers. Photonic band structures were calculated for the inverted, orientationally- ordered monoclinic geometry, systematically varying [1] the shape parameters of lobe fusion and lobe symmetry for the tangent dimer condition and [2] the filling fraction of dielectric materials beyond close-packing. Full 8-9 photonic bandgaps (red arrow) were found for select arrangements. Additionally, the 2-3 partial bandgap for a spherocylinder-based crystal was probed using reflection spectroscopy at normal incidence.

I. D. Hosein, S. H. Lee, A. Lee, C. M. Liddell. Advanced Functional Materials, 20.18 (2010): 3085-3091.

[a]

[b]

[c]

[d]

[e]

Chekesha M. Liddell, Cornell University, DMR 0547976

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Liddell’s professional outreach activities include mentoring underrepresented minorities and women in STEM fields at various stages in their career paths

Education & Outreach

While on sabbatical at HBCU Norfolk State University (NSU) in the Spring of 2010, Liddell held interactive professional development presentations, including topics such as publishing research in high impact archival journals―

Center for Materials Research Graduate Seminar, “Navigating the Graduate School Experience toward Academic Careers,” Mar. 19, 2010. (shown at right)

Dozoretz Undergraduate Scholars Applied Science Seminar, “So You Want to Go to Graduate School,” Apr. 28, 2010.

Liddell also critiqued content, delivery, and visual aids as a judge of graduate student presentations for the Seventh Annual ‘Optics is Light Work’ Student Poster Competition, NSU Student Chapter of the Optical Society of America, Apr. 30, 2010.

Chekesha M. Liddell, Cornell University, DMR 0547976