Singlets and triplets in hybrid nanodevices
V. M. Agranovich+, O. A. Dubovskii*, G. C. La Rocca×
+Institute of Spectroscopy of the RAS, 142190 Troitsk, Russia
*Institute of Physical and Power Engineering, 249033 Obninsk, Russia
×Scuola Normale Superiore and CNISM, 56126 Pisa, Italy
Abstract
An organic material thin layer can be used to resonantly
absorb light and nonradiatively transfer excitation to an adjacent
inorganic quantum well the optical nonlinearities of which can in
this way be turned on more efficiently than by direct optical
pumping. We theoretically consider this process in a hybrid
structure based on crystalline tetracene in which the singlet
exciton energy is close to twice the one of a triplet exciton and
thermally activated singlet exciton fission into two triplets can
be efficient. We investigate how the temperature dependence of
the singlet exciton diffusion length affects the functional
properties of such hybrid organic-inorganic nanostructures based
on tetracene. We show how temperature activated fission opens a
new possibility to turn on and off the indirect pumping due to
energy transfer from the organic into the inorganic subsystem.