Antenna-Enhanced Optoelectronic Probing of Carbon Nanotubes

Abstract

We report on the first antenna-enhanced optoelectronic microscopy studies on nanoscale devices. By coupling the emission and excitation to a scanning optical antenna, we are able to locally enhance the electroluminescence and photocurrent along a carbon nanotube device. We show that the emission source of the electroluminescence can be pointlike with a spatial extension below 20 nm. Topographic and antenna-enhanced photocurrent measurements reveal that the emission takes place at the location of highest local electric field indicating that the mechanism behind the emission is the radiative decay of excitons created via impact excitation.

Tailored nanoantennas for directional Raman studies of individual carbon nanotubes

“…For instance, in our experiment the combination of RBM and G mode data (measured at λ L = 532 nm) allows us to conclude [31] that the bundle B likely contains a (22,15) CNT. The bundle C contains a semiconducting CNT with either (26,0) or (25,2) chiral indices (λ L = 532 nm) and a metallic CNT with either (21,6) or (20,8) [46]. Further details about our assignment procedure are discussed in the Appendixes.…”

“…The RBM peak is centered at (130 ± 2) cm −1 , which corresponds to a diameter d = (1.95 ± 0.04) nm. Table III shows the two metallic CNTs [ (21,6) and (20,8)] within the window [E ii = (2.330 ± 0.100) eV; d = (1.95 ± 0.04) nm]. Between them, the most likely assignment is (21,6), owing to the smaller E ii − E L value [53].…”

“…Table III shows the two metallic CNTs [ (21,6) and (20,8)] within the window [E ii = (2.330 ± 0.100) eV; d = (1.95 ± 0.04) nm]. Between them, the most likely assignment is (21,6), owing to the smaller E ii − E L value [53]. Figure 9 shows the γ dependence of the Raman spectrum around the G mode for the portion of bare bundle in between the antenna arrays A 0 • and A 30 • in sample C. The measurement completes the data shown in Fig.…”

“…This particular choice is motivated by the fact that the Raman spectrum of graphene is well known, and it is relatively easy to transfer a single layer on top of selected patterned structures. However, owing to their extremely anisotropic optical properties, carbon nanotubes (CNTs) appear in many respects to be more intriguing candidates for target structures [19][20][21][22]. Raman spectroscopy of individual CNTs is usually difficult, due to their small cross section.…”

Mechanism of surface treatments on carbon nanotube transparent conductive films by three different reagents

“…5 Carbon nanotubes (CNTs) have attracted a lot of research attention due to their specic structure and excellent mechanical, optical and electrical properties, 6,7 and thus have been used in diverse elds as transistors, 8 storage devices, 9 and optoelectronic devices. 10 CNT incorporated transparent conductive lms (CNT-TCFs) can be used in a exible electroluminescent device because CNTs can also be introduced as a hole injection buffer layer on ITO to realize a high brightness organic light emitting diode (OLED). 11,12 CNT-TCFs can be prepared by direct growth, solution deposition, spray coating, and vacuum ltration methods.…”