Nonradiative Recombination of Excitons in Carbon Nanotubes Mediated by Free Charge Carriers

Free electrons or holes can mediate the nonradiative recombination of excitons in carbon nanotubes. Kinematic constraints arising from the quasi-one-dimensional nature of excitons and charge carriers lead to a thermal activation barrier for the process. However, a model calculation suggests that the rate of recombination mediated by a free electron is the same order of magnitude as that of two-exciton recombination. Small amounts of doping may contribute to the short exciton lifetimes and low quantum yields observed in carbon nanotubes. Disciplines Physical Sciences and Mathematics | Physics Comments Suggested Citation: J.M. Kinder and E.J. Mele. (2008). "Nonradiative recombination of excitons in carbon nanotubes mediated by free charge carriers." Physical Review B. 78, 155429. © 2008 The American Physical Society http://dx.doi.org/10.1103/PhysRevB.78.155429. This journal article is available at ScholarlyCommons: http://repository.upenn.edu/physics_papers/86 Nonradiative recombination of excitons in carbon nanotubes mediated by free charge carriers J. M. Kinder* and E. J. Mele Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA Received 5 August 2008; revised manuscript received 3 October 2008; published 27 October 2008 Free electrons or holes can mediate the nonradiative recombination of excitons in carbon nanotubes. Kinematic constraints arising from the quasi-one-dimensional nature of excitons and charge carriers lead to a thermal activation barrier for the process. However, a model calculation suggests that the rate of recombination mediated by a free electron is the same order of magnitude as that of two-exciton recombination. Small amounts of doping may contribute to the short exciton lifetimes and low quantum yields observed in carbon nanotubes. DOI: 10.1103/PhysRevB.78.155429 PACS number s : 71.35. y, 78.67.Ch, 78.55. m