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Science, First Release (9 mars 2017)

Cutting edges for exciton on hybrid perovskites

 

Extremely efficient internal exciton dissociation through edge-states in layered 2D perovskites

Understanding and controlling the transport of electrical charges and energy flow in low-dimensional semiconductors, such as quantum wells, have led to the development of high-performance optoelectronic devices.

The quantum confinement in these wells usually leads to photo-generated charges : electron-hole pairs or "excitons", strongly linked by Coulomb interactions. The joint efforts of the teams of Los Alamos, Northwestern, Brookhaven and Rennes have shown that this phenomenon is much richer in the thin films of lamellar hybrid perovskites.
In these materials, alternating layers of organic molecules (in this case butylammonium) are separated by an organic-inorganic hybrid layer in which the cavities left by the PbI 6 octahedra are filled with methylammonium cations.

 
© J.-C. Blancon/LANL
 

When the thickness of this hybrid layer is at least 3 octahedrons, the Franco-American consortium has demonstrated the emergence of edge states that allow the spontaneous conversion of electron-hole pairs into free charge carriers. This phenomenon has major implications for the performance of perovskite layered devices as demonstrated in the case of solar cells and light-emitting diodes.

 
Contacts
Jacky EVEN, Fonctions Optiques pour les Technologies de l’informatiON (Foton)
jacky.even insa-rennes.fr
+33 2 23 23 82 95 / +33 6 88 99 32 60
Laurent PEDESSEAU, Fonctions Optiques pour les Technologies de l’informatiON (Foton)
laurent.pedesseau insa-rennes.fr
+33 2 23 23 88 69
Claudine KATAN, Institut des sciences chimiques de Rennes (ISCR)
claudine.katan univ-rennes1.fr
+33 2 23 23 56 82
Mikaël KEPENEKIAN, Institut des sciences chimiques de Rennes (ISCR)
mikael.kepenekian univ-rennes1.fr
+33 2 23 23 31 59
 
Partners

LANL (Los Alamos, USA), Northwestern University (Evanston, USA), BNL (Upton, USA), Rice University (Houston, USA)

 
Reference

Extremely efficient internal exciton dissociation through edge-states in layered 2D perovskites, J.-C. Blancon, H. Tsai, W. Nie, C. C. Stoumpos, L. Pedesseau, C. Katan, M. Kepenekian, C. M. M. Soe, K. Appavoo, M. Y. Sfeir, S. Tretiak, P. M. Ajayan, M. G. Kanatzidis, J. Even, J. J. Crochet, A. D. Mohite. Science 9 mars 2017 [1], DOI : 10.1126/science.aal4211

Voir en ligne :


[1This paper will be published online by the journal Science and AAAS, via « First Release », on Thursday, 9 March 2017 (the article will appear at a later date in print)