Abstract
We address recent experiments (Science 2009, 325, 1367) reporting on highly efficient multiplication of electron-hole pairs in carbon nanotube photodiodes at photon energies near the carrier multiplication threshold (twice the quasi-particle band gap). This result is surprising in light of recent experimental and theoretical work on multiexciton generation in other confined materials, such as semiconducting nanocrystals. We propose a detailed mechanism based on carrier dynamics and impact excitation resulting in highly efficient multiplication of electron-hole pairs. We discuss the important time and energy scales of the problem and provide analysis of the role of temperature and the length of the diode.
Original language | English |
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Pages (from-to) | 3277-3282 |
Number of pages | 6 |
Journal | Nano Letters |
Volume | 10 |
Issue number | 9 |
DOIs | |
State | Published - 8 Sep 2010 |
Keywords
- Carbon nanotubes
- diode
- impact excitation
- multiexcitons
- photocurrents