title: Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates.
abstract: We used photoactive substrates consisting of about 1 nm coating of a metal oxide on glass substrates to investigate the impact of the structures of colloidal quantum dots on their photophysical and photochemical properties. We showed during irradiation these substrates can interact uniquely with such quantum dots, inducing distinct forms of photo-induced processes when they have different cores, shells, or ligands. In particular, our results showed that for certain types of core-shell quantum dot structures an ultrathin layer of a metal oxide can reduce suppression of quantum efficiency of the quantum dots happening when they undergo extensive photo-oxidation. This suggests the possibility of shrinking the sizes of quantum dots without significant enhancement of their non-radiative decay rates. We show that such quantum dots are not influenced significantly by Coulomb blockade or photoionization, while those without a shell can undergo a large amount of photo-induced fluorescence enhancement via such blockade when they are in touch with the metal oxide.
authors.affiliation: Department of Physics, University of Alabama in Huntsville , Huntsville, Alabama 35899, USA.
authors.forename: Kira
authors.initials: K
authors.lastname: Patty
authors.forename: Seyed M
authors.initials: SM
authors.lastname: Sadeghi
authors.affiliation: Department of Physics, University of Alabama in Huntsville , Huntsville, Alabama 35899, USA.
authors.forename: Quinn
authors.initials: Q
authors.lastname: Campbell
authors.affiliation: Department of Physics, University of Alabama in Huntsville , Huntsville, Alabama 35899, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Hamilton
authors.affiliation: Department of Physics, University of Alabama in Huntsville , Huntsville, Alabama 35899, USA.
authors.forename: Robert G
authors.initials: RG
authors.lastname: West
authors.affiliation: Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma , Norman, Oklahoma 73019, USA.
authors.forename: Chuanbin
authors.initials: C
authors.lastname: Mao