Self-decoupled porphyrin with a tripodal anchor for molecular-scale electroluminescence.
A self-decoupled porphyrin with a tripodal anchor has been synthesized and deposited on Au(111) using different wet-chemistry methods. Nanoscale electroluminescence from single porphyrin molecules or aggregates on Au(111) has been realized by tunneling electron excitation. The molecular origin of the luminescence is established by the vibrationally resolved fluorescence spectra observed. The rigid tripodal anchor not only acts as a decoupling spacer but also controls the orientation of the molecule. Intense molecular electroluminescence can be obtained from the emission enhancement provided by a good coupling between the molecular transition dipole and the axial nanocavity plasmon. The unipolar performance of the electroluminescence from the designed tripodal molecule suggests that the porphyrin molecule is likely to be excited by the injection of hot electrons, and then the excited state decays radiatively through Franck-Condon π*-π transitions. These results open up a new route to generating electrically driven nanoscale light sources.
Hefei National Laboratory for Physical Sciences at the Microscale and ‡CAS Key Laboratory of Soft Matter Chemistry and Department of Chemistry, University of Science and Technology of China , Hefei, Anhui 230026, China.
San-E
SE
Zhu
Yan-Min
YM
Kuang
Feng
F
Geng
Jia-Zhe
JZ
Zhu
Cong-Zhou
CZ
Wang
Yun-Jie
YJ
Yu
Yang
Y
Luo
Yang
Y
Xiao
Kai-Qing
KQ
Liu
Qiu-Shi
QS
Meng
Li
L
Zhang
Song
S
Jiang
Yang
Y
Zhang
Guan-Wu
GW
Wang
Zhen-Chao
ZC
Dong
J G
JG
Hou