Efficient near-infrared up-conversion photoluminescence in carbon nanotubes

• DOI: 10.1038/ncomms9920
• Publication Date: 2015-11-16T12:01:45Z
• Authors: Naoto Akizuki; Shun Aota; Shinichiro Mouri; Kazunari Matsuda; Yuhei Miyauchi
• Keywords: Photoexcitation; Photoluminescence excitation

Abstract Photoluminescence phenomena normally obey Stokes’ law of luminescence according to which the emitted photon energy is typically lower than its excitation counterparts. Here we show that carbon nanotubes break this rule under one-photon conditions. We found exhibit efficient near-infrared photoluminescence upon photoexcitation even at an lying >100–200 meV below emission room temperature. This apparently anomalous phenomenon attributed one-phonon-assisted up-conversion processes resulting from unique excited-state dynamics emerging in individual nanotube with accidentally or intentionally embedded localized states. These findings may open new doors for harvesting, optoelectronics and deep-tissue imaging optical range.