WP6 : metrology of the metal/semiconductor ratio (MSR) Goal : developing a routine method to measure the MSR Optical spectroscopy technique(s) : * optical absorption (OA) * photoluminescence excitation (PLE) * resonant Raman spectroscopy (RR)

E 11 fluorescence E 22 absorption hole e-e- Optical properties : absorption/emission (PL, fluorescence)

E 11 fluorescence E 22 absorption hole e-e- Optical properties : absorption/emission (PL, fluorescence) Optical transitions involve excitonic states!

(9,0) (metallic)(10,0) (semi-conducting) (from Saito et al) Electronic and optical properties (from Jorio et al) ‘‘Kataura plot’’

(9,0) (metallic)(10,0) (semi-conducting) (from Saito et al) Electronic and optical properties (from Jorio et al) ‘‘Kataura plot’’ !! The E ii vary depending on the environment : individual/bundles, gas/liquid matrix, surfactant/substrate… !!

Arc electric sample (1.2 nm<d<1.5 nm) E 11,sc E 22,sc E 11,met (from Izard et al) Optical properties : absorption

E 11,sc E 22,sc E 11,met Arc electric sample (1.2 nm<d<1.5 nm) (from Izard et al) Optical properties : absorption

M.J. O’Connell et al., Science 297 (2002) 593 UnbundlingSynthesis of individual SWNTs J. Kong et al., Nature 395 (1998) 878 Optical properties : emission (PL, fluorescence) Only observed on individual semiconducting SWNT (no contacts with metallic) Excitation (661 nm) Emission (850 nm)

Bachilo et al, Science, 298, 2361 (2002) Optical properties : NIR fluorescence Identification of a (n,m) nanotube from the couple (E ii,E 11 ) HiPCO sample (0.7 nm<d<1.3 nm)

10 Optical properties : Raman scattering

11 Optical properties : resonant Raman scattering

Résonance : Optical / vibrational properties : (resonant) Raman scattering Mode de respiration radial (RBM) Modes d'élongation tangentiels (TM or G-band) 200 cm cm cm cm -1 A 1g E 1g E 2g

Profil métallique Pics assymétriques, couplages électrons-phonons 2.41 eV 1.92 eV Profil semiconducteur Pics symétriques, lorentziens (cm ) Intensité Raman (u.a.) Resonant Raman scattering E=2.41 eV ( =514.5 nm) E=1.92 eV ( =647.1 nm)

Resonant Raman scattering Arc electric sample (1.2 nm<d<1.5 nm) CVD (HiPCO) sample (0.7 nm<d<1.3 nm) RBM (cm -1 ) =A/d + B (A≈224, B≈14 cm -1 ) Identification of a (n,m) nanotube from the couple (E ii, RBM )

WP6 : metrology of the metal/semiconductor ratio (MSR) Goal : developing a routine method to measure the MSR Optical spectroscopy technique(s) : absorption, PLE, RR Method 1 : optical absorption in surfactant-based dispersion   narrowing of the spectroscopic signatures   avoids texture-induced effects   one has to know the OA coefficients Alternative : measurements on transparent quartz substrates Method 2 : RR spectroscopy (any substrate)   very high sensitivity and selectivity   one has to mesure the E ii and select a couple of E laser   one has to measure the RR cross sections (coupling with method 1) Alternatives : relative (semi-quantitative) measurements Couplings with PLE and TEM will help!