n-Type Transparent Conducting Films of Small Molecule and Polymer Amine Doped Single-Walled Carbon Nanotubes

Abstract

In this report, we investigate the electrical and optical properties of thin conducting films of SWNTs after treatment with small molecule and polymeric amines. Among those tested, we find hydrazine to be the most effective n-type dopant. We use absorbance, Raman, X-ray photoelectron, and nuclear magnetic resonance spectroscopies on thin conducting films and opaque buckypapers treated with hydrazine to study fundamental properties and spectroscopic signatures of n-type SWNTs and compare them to SWNTs treated with nitric acid, a well-characterized p-type dopant. We find that hydrazine physisorbs to the surface of semiconducting and metallic SWNTs and injects large electron concentrations, raising the Fermi level as much as 0.7 eV above that of intrinsic SWNTs. Hydrazine-treated transparent SWNT films display sheet resistances nearly as low as p-type nitric-acid-treated films at similar optical transmittances, demonstrating their potential for use in photovoltaic devices as low work function transparent electron-collecting electrodes.

Strong Acoustic Phonon Localization in Copolymer-Wrapped Carbon Nanotubes

“…41 While the data follow the trend quite well, remaining variations are likely caused by the varying degree of residual strain from tube to tube 42 and/or the different amount of chirality dependent phonon frequency shifts. 43 The observed isotope shift for individual SWCNTs is 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 9 also in excellent agreement with previous findings carried out with large ensembles of SWCNTs from the same LV growth chamber 44,45 as well as CVD grown SWCNTs. 46 For these isotope engineered SWCNTs, the signature of exciton emission was confirmed in each case by the laser detuning technique described in Figure 2 with yields of about 10%-30% for finding (6,4) chirality SWCNTs, with the exception of the 100% 13 C samples where we found no PL signal around 890 nm that would correspond to (6,4) for 20% 13 C admixing.…”

Building interconnects in carbon nanotube networks with metal halides for transparent electrodes

“…Dopants including halogen (Br 2 ) [24], acids (HNO 3 , HCl) [25,26], chlorides (FeCl 3 , AuCl 3 ) [27,28], metal particles (Au, Ag, Ni) [29,30], metal oxides (MoO x ) [31], and organic molecules [32] were widely investigated. Those efforts greatly improved the electrical conductivity of CNT films, resulting in R s of 50-100 X/sq at 85-90% transmittance.…”

New insights into the oxidation of single-walled carbon nanotubes for the fabrication of transparent conductive films

“…Removal of the ACFs allowed the formation of a network of unmodified nanotubes, which improved the electrical conductivity of the network. The performances of the TCFs reported in this study may be further improved by controlling the dispersion conditions and the chemical doping methods [9,36,46,47]. This work highlights the potential of oxidative methods for preparing SWCNT-based TCFs for use in optoelectronic applications.…”