Hi,
I came across a recent publication in nature where a structure was fabricated to be used as an optical rectenna. Linked here.
http://www.nature.com/nnano/journal/v10/n12/full/nnano.2015.220.html
They had mentioned the use of MWCNTs sandwitched between two metal substrates and this structure helps in rectifying ac optical frequencies to dc. We would like to have an application with the same structure but with low RF frequencies (in the range of 5 - 20 MHz). My claim is that the design and chiral factor of MWCNTs decide its response to a specific frequency. I would like to know what properties and changes to consider for the structure to respond to low frequencies. It was also mentioned in the work and I quote "Carbon nanotubes can be used to absorb electromagnetic radiation in essentially the entire electromagnetic spectrum by both free carrier (intraband) and excitonic (interband) absorption processes"
Thanks in advance.
I understand the effect in the following way: Optical excitation in metal films or nanostructure is mediated by plasmon resonances either localized or surface waves. Plasmons can be excited/dexcited by absorbing/emitting a hot electron which can be transformed in to current . The effective Voltage will amount to the photon enery that was absorbed/emitted.
The demonstration of this effect started in photoemission at STM tips upon tunneling at optical frequencies somewhere in the 70's.
In the last few year there were a renewed interest in this field for nanodevices like the work you cited. as well as my work:
http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b04622
This was demonstrated as well in the MW/RF regime in these works and many others:
1. Bright Side of the Coulomb Blockade
M. Hofheinz, F. Portier, Q. Baudouin, P. Joyez, D. Vion, P. Bertet, P. Roche, and D. Esteve
Phys. Rev. Lett. 106, 217005 – Published 27 May 2011
2. http://www.nature.com/nature/journal/v490/n7420/abs/nature11559.html
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