TY - JOUR
T1 - Low-Temperature Single Carbon Nanotube Spectroscopy of sp3 Quantum Defects
AU - He, Xiaowei
AU - Gifford, Brendan J.
AU - Hartmann, Nicolai F.
AU - Ihly, Rachelle
AU - Ma, Xuedan
AU - Kilina, Svetlana V.
AU - Luo, Yue
AU - Shayan, Kamran
AU - Strauf, Stefan
AU - Blackburn, Jeffrey L.
AU - Tretiak, Sergei
AU - Doorn, Stephen K.
AU - Htoon, Han
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/11/28
Y1 - 2017/11/28
N2 - Aiming to unravel the relationship between chemical configuration and electronic structure of sp3 defects of aryl-functionalized (6,5) single-walled carbon nanotubes (SWCNTs), we perform low-temperature single nanotube photoluminescence (PL) spectroscopy studies and correlate our observations with quantum chemistry simulations. We observe sharp emission peaks from individual defect sites that are spread over an extremely broad, 1000-1350 nm, spectral range. Our simulations allow us to attribute this spectral diversity to the occurrence of six chemically and energetically distinct defect states resulting from topological variation in the chemical binding configuration of the monovalent aryl groups. Both PL emission efficiency and spectral line width of the defect states are strongly influenced by the local dielectric environment. Wrapping the SWCNT with a polyfluorene polymer provides the best isolation from the environment and yields the brightest emission with near-resolution limited spectral line width of 270 μeV, as well as spectrally resolved emission wings associated with localized acoustic phonons. Pump-dependent studies further revealed that the defect states are capable of emitting single, sharp, isolated PL peaks over 3 orders of magnitude increase in pump power, a key characteristic of two-level systems and an important prerequisite for single-photon emission with high purity. These findings point to the tremendous potential of sp3 defects in development of room temperature quantum light sources capable of operating at telecommunication wavelengths as the emission of the defect states can readily be extended to this range via use of larger diameter SWCNTs.
AB - Aiming to unravel the relationship between chemical configuration and electronic structure of sp3 defects of aryl-functionalized (6,5) single-walled carbon nanotubes (SWCNTs), we perform low-temperature single nanotube photoluminescence (PL) spectroscopy studies and correlate our observations with quantum chemistry simulations. We observe sharp emission peaks from individual defect sites that are spread over an extremely broad, 1000-1350 nm, spectral range. Our simulations allow us to attribute this spectral diversity to the occurrence of six chemically and energetically distinct defect states resulting from topological variation in the chemical binding configuration of the monovalent aryl groups. Both PL emission efficiency and spectral line width of the defect states are strongly influenced by the local dielectric environment. Wrapping the SWCNT with a polyfluorene polymer provides the best isolation from the environment and yields the brightest emission with near-resolution limited spectral line width of 270 μeV, as well as spectrally resolved emission wings associated with localized acoustic phonons. Pump-dependent studies further revealed that the defect states are capable of emitting single, sharp, isolated PL peaks over 3 orders of magnitude increase in pump power, a key characteristic of two-level systems and an important prerequisite for single-photon emission with high purity. These findings point to the tremendous potential of sp3 defects in development of room temperature quantum light sources capable of operating at telecommunication wavelengths as the emission of the defect states can readily be extended to this range via use of larger diameter SWCNTs.
KW - carbon nanotubes
KW - diazonium doping
KW - electronic structure
KW - exciton localization
KW - photoluminescence
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U2 - 10.1021/acsnano.7b03022
DO - 10.1021/acsnano.7b03022
M3 - Article
C2 - 28958146
AN - SCOPUS:85035353634
SN - 1936-0851
VL - 11
SP - 10785
EP - 10796
JO - ACS Nano
JF - ACS Nano
IS - 11
ER -