Photogenerated exciton dissociation in highly coupled lead salt nanocrystal assemblies.
Internanocrystal coupling induced excitons dissociation in lead salt nanocrystal assemblies is investigated. By combining transient photoluminescence spectroscopy, grazing incidence small-angle X-ray scattering, and time-resolved electric force microscopy, we show that excitons can dissociate, without the aid of an external bias or chemical potential gradient, via tunneling through a potential barrier when the coupling energy is comparable to the exciton binding energy. Our results have important implications for the design of nanocrystal-based optoelectronic devices.
Choi
Joshua J
JJ
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA. jwc47@cornell.edu
Luria
Justin
J
Hyun
Byung-Ryool
BR
Bartnik
Adam C
AC
Sun
Liangfeng
L
Lim
Yee-Fun
YF
Marohn
John A
JA
Wise
Frank W
FW
Hanrath
Tobias
T
D007854:Lead / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry / Q000528:radiation effects; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects; D010316:Particle Size; D012492:Salts / Q000737:chemistry / Q000528:radiation effects; D013499:Surface Properties
D046911:Macromolecular Substances; D012492:Salts; D007854:Lead