A carbon nanotube optical rectenna

Abstract

An optical rectenna--a device that directly converts free-propagating electromagnetic waves at optical frequencies to direct current--was first proposed over 40 years ago, yet this concept has not been demonstrated experimentally due to fabrication challenges at the nanoscale. Realizing an optical rectenna requires that an antenna be coupled to a diode that operates on the order of 1 PHz (switching speed on the order of 1 fs). Diodes operating at these frequencies are feasible if their capacitance is on the order of a few attofarads, but they remain extremely difficult to fabricate and to reliably couple to a nanoscale antenna. Here we demonstrate an optical rectenna by engineering metal-insulator-metal tunnel diodes, with a junction capacitance of ∼2 aF, at the tip of vertically aligned multiwalled carbon nanotubes (∼10 nm in diameter), which act as the antenna. Upon irradiation with visible and infrared light, we measure a d.c. open-circuit voltage and a short-circuit current that appear to be due to a rectification process (we account for a very small but quantifiable contribution from thermal effects). In contrast to recent reports of photodetection based on hot electron decay in a plasmonic nanoscale antenna, a coherent optical antenna field appears to be rectified directly in our devices, consistent with rectenna theory. Finally, power rectification is observed under simulated solar illumination, and there is no detectable change in diode performance after numerous current-voltage scans between 5 and 77 °C, indicating a potential for robust operation.

Coherence lifetime broadened optical transitions in a 2 atom diameter HgTe nanowire: a temperature dependent resonance Raman study

“…In the case of carbon nanotubes the discrete energies are due to excitonic transitions and there are good reasons for believing the transition responsible for the Raman resonance in the HgTe nanowires is also excitonic. Whether practical applications of the coherence of optical transitions in 1D systems can be developed is still unclear, however the optical properties of carbon nanotubes is generating a huge amount of interest 28,29 and small diameter nanowires such as the ones investigated in this paper are likely to bring additional new complementary features to this field.…”

High Performance Multiwall Carbon Nanotube–Insulator–Metal Tunnel Diode Arrays for Optical Rectification

“…They reported asymmetry and nonlinearity values up to 8 with total barrier thickness below 5 nm. [26] The previous devices were able to operate at very high frequency (560 THz), but needed low work function Ca (2.9 eV) as a top metal to generate suitable asymmetry against the ≈5 eV work function MWCNT electrodes. The device structure (Figure 2a) uses an array of vertically aligned multiwall carbon nanotubes (MWCNTs) that are coated in a thin layer of dielectric using atomic layer deposition (ALD) then a metal electrode layer is deposited on top.…”

Smart Fabrics and Networked Clothing: Recent developments in CNT-based fibers and their continual refinement

“…As a result, this has limited the adoption of these CNT materials and provided an indication that CNT communications might be limited to short-range applications. <AU: Please check whether the preceding edited sentence conveys the intended meaning.> The application of CNTs at very high optical frequencies has recently been reported in Nature Nanotechnology as the first operating CNT optical rectenna [18]. A rectenna is an antenna that operates in the optical frequencies.…”