title: Coherent exciton delocalization in strongly coupled quantum dot arrays.
abstract: Quantum dots (QDs) coupled into disordered arrays have exhibited the intriguing property of bulk-like transport while maintaining discrete excitonic optical transitions. We have utilized ultrafast cross-polarized transient grating (CPTG) spectroscopy to measure electron-hole wave function overlap in CdSe QD films with chemically modified surfaces for tuning inter-QD electronic coupling. By comparing the CPTG decays with those of isolated QDs, we find that excitons coherently delocalize to form excited states more than 200% larger than the QD diameter.
authors.affiliation: National Renewable Energy Laboratory , 15013 Denver West Pkwy, Golden, Colorado 80401, United States.
authors.forename: Ryan W
authors.initials: RW
authors.lastname: Crisp
authors.forename: Joel N
authors.initials: JN
authors.lastname: Schrauben
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Beard
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Luther
authors.forename: Justin C
authors.initials: JC
authors.lastname: Johnson
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D004579:Electron Transport; D004583:Electrons; D055095:Optics and Photonics; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; C058667:cadmium selenide