Home
For authors
Submission status

Archive
Archive (English)
Current
      Volume 108
      Volume 107
      Volume 106
      Volume 105
      Volume 104
      Volume 103
      Volume 102
      Volume 101
      Volume 100
      Volume 99
      Volume 98
      Volume 97
      Volume 96
      Volume 95
      Volume 94
      Volume 93
Search
VOLUME 101 | ISSUE 1 | PAGE 19
Quantum auto-ionization of molecular excitons and photovoltaic conversion
Abstract
This paper explores a novel way of charge separation (auto-ionization) of molecular excitons, by quantum tunneling through nano-size p-n junction. This mechanism can dominate the standard one (i.e., when Frenkel exciton is ionized at donor or acceptor impurity sites) for very short, nano-size, p-n junction, where the junction electric field can be strong for relatively small (on the order of 1 V) voltage drop. Within a simple one-dimensional model for the depletion region of the p-n junction (donor and acceptor reservoirs connected by a short molecular wire) we compute the quantum yield Yb for the tunneling exciton auto-ionization in the "bulk" of the depletion region. For modern organic photo-sensitive materials with p-n junction size on the order of 10-20 nm, Yb could be close to 1. Such a high efficiency of the charge separation (one of the main factor entering figure of merit, indicating how good are photovoltaic conversion cells) makes this new mechanism potentially very perspective for the applications.