Photocurrents induced by stimulated absorption of light

Alexey Kavokin, Giuseppe Eramo

.

DOI: 10.4236/ns.2010.21010                

Abstract

In organic materials absorption of light results in creation of the Frenkel excitons, Coulomb -bound electron-hole pairs having an integer spin. Being composite bosons, Frenkel excitons may accumulate in significant quantities in a single quantum state. The probability of photon absorption by such a state increases as (N+1) where N is the occupation number of the state. This enhancement is due to the stimulated ab-sorption of light, which is a final-state stimu-lated process analogous to the well-known stimulated emission of light. We propose using the stimulated absorption for creation of solar cells of a record quantum efficiency. We are going to use the organic microspheres to ac-cumulate the Frenkel excitons at the discrete frequencies corresponding to the photonic whispering gallery modes of the sphere. The dissociation of accumulated Frenkel excitons will be effectuated periodically using the trans-parent carbon contacts on a piezoelectric mechnical support.

Keywords

SolarCell; Photovoltaics; Exciton; Bose-EinsteinCondensation

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Kim, J., Lee, K., Coates, N., Moses, D., Nguyen, T., Dante, M., Heeger, A. (2007) Efficient tandem polymer solar cells fabricated by all-solution processing. Science, 222, 317-5835.
[2]	Mott, N.F. (1938) Conduction in polar crystals. II. The conduction band and ultra-violet absorption of al-kali-halide crystals. Trans. Faraday Soc, 34, 500.
[3]	Frenkel, J. (1931) On the transformation of light into heat in solids. I, Phys. Rev. 3, 17.
[4]	Kasprzak, J. et al. (2006) Bose-einstein condensation of exciton polaritons. Nature, 443, 409.
[5]	Balili, R., Hartwell, V., Snoke, D., Pfeiffer, L. and West, K. (2007) Bose-einstein condensation of microcavity po-laritons in a trap. Science, 316, 1007.
[6]	Lai, C.W., Kim, N.Y., Utsunomiya, S., Roumpos, G., Deng, H., Fraser, M.D., Byrnes, T., Recher, P., Kumada, N., Fujisawa, T. and Yamamoto, Y. (2007) Coherent zero-state and pi-state in an exciton-polariton condensate array. Nature, 450, 529.
[7]	Christopoulos, S. et al. (2007) Room temperature polari-ton lasing in semiconductor microcavities. Phys. Rev. Lett. 98, 126405.
[8]	Christmann, G. et al. (2008)Room temperature polariton lasing in a GaN/AlGaN multiple quantum well micro-cavity. Appl. Phys. Lett. 93, 051102.