Exciton antennas and concentrators from core-shell and corrugated carbon nanotube filaments of homogeneous composition

Jae-Hee Han, Massachusetts Institute of Technology
Geraldine LC Paulus, Massachusetts Institute of Technology
Ryuichiro Maruyama, Sony Corp.
Daniel A. Heller, Massachusetts Institute of Technology
Woo-Jae Kim, Kyungwon University
Paul W. Barone, Massachusetts Institute of Technology
Chang Young Lee, Massachusetts Institute of Technology
Jong Hyun Choi, Birck Nanotechnology Center, Purdue University
Moon-Ho Ham, Massachusetts Institute of Technology
Changsik Song, Massachusetts Institute of Technology
C Fantini, Univ Fed Minas Gerais
Michael S. Strano, Massachusetts Institute of Technology

Date of this Version



Nature Materials 9, 833–839 (2010)

This document has been peer-reviewed.



There has been renewed interest in solar concentrators and optical antennas for improvements in photovoltaic energy harvesting and new optoelectronic devices. In this work, we dielectrophoretically assemble single-walled carbon nanotubes (SWNTs) of homogeneous composition into aligned filaments that can exchange excitation energy, concentrating it to the centre of core-shell structures with radial gradients in the optical bandgap. We find an unusually sharp, reversible decay in photoemission that occurs as such filaments are cycled from ambient temperature to only 357 K, attributed to the strongly temperature-dependent second-order Auger process. Core-shell structures consisting of annular shells of mostly (6, 5) SWNTs (E-g = 1.21 eV) and cores with bandgaps smaller than those of the shell (E-g = 1.17 eV (7, 5)-0.98 eV (8, 7)) demonstrate the concentration concept: broadband absorption in the ultraviolet-near-infrared wavelength regime provides quasi-singular photoemission at the (8, 7) SWNTs. This approach demonstrates the potential of specifically designed collections of nanotubes to manipulate and concentrate excitons in unique ways.


Engineering | Nanoscience and Nanotechnology