Unlike a semiconductor, where the absorption is limited by the band gap, a “microrectenna array” could theoretically very efficiently rectify any desired portion of the infrared frequency spectrum (25 - 400 THz). We investigated vertical metal-insulator-metal (MIM) diodes that rectify vertical high-frequency fields produced by a metamaterial planar stripe-teeth Al or Au array (above the diodes), similar to stripe arrays that have demonstrated near-perfect absorption in the infrared due to critical coupling . Using our design rules that maximize asymmetry (and therefore the component of the electric field pointed into the substrate, analogous to Second Harmonic Generation), we designed, fabricated, and analyzed these metamaterial-based microrectenna arrays. NbOx and Al2O3 were produced by anodization and ALD, respectively. Smaller visible-light Pt-NbOx-Nb rectennas have produced output power when illuminated by visible (514 nm) light .
The resonances of these new Au/NbOx/Nb and Al/Al2O3/Al microrectenna arrays, with larger dimensions and more complex nanostructures than in Ref. 1, were characterized by microscopic FTIR microscopy and agreed well with FDTD models, once the experimental refractive index values were entered into the model. Current-voltage measurements were carried out, showed that the Al/Al2O3/Al diodes have very large barrier heights and breakdown voltages, and were compared to our model of the MIM diode. We calculate expected THz-rectification using classical  and quantum  rectification models, and compare to measurements of direct current output, under infrared illumination.
 C. Wu, et. al., Phys. Rev. B 84 (2011) 075102.
 R. M. Osgood III, et. al., Proc. SPIE 8096, 809610 (2011).
 A. Sanchez, et. al., J. Appl. Phys. 49 (1978) 5270.
 J. R. Tucker and M. J. Feldman, Rev. of Mod. Phys. 57, (1985)1055.
Richard M. Osgood III, Stephen A. Giardini, Joel B. Carlson, Prabhuram Joghee, Ryan P. O'Hayre, Kenneth Diest, and Mordechai Rothschild, "Stripe-teeth metamaterial Al- and Nb-based rectennas (Presentation Recording)," Proc. SPIE 9544, Metamaterials, Metadevices, and Metasystems 2015, 95441W (Presented at SPIE Nanoscience + Engineering: August 12, 2015; Published: 5 October 2015); https://doi.org/10.1117/12.2188779.4519316167001.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the proceedings. They include the speaker's narration with video of the slides and animations. Most include full-text papers. Interactive, searchable transcripts and closed captioning are now available for most presentations.
Search our growing collection of more than 26,000 conference presentations, including many plenaries and keynotes.