1 research outputs found
Visible Photoluminescence Components of Solution-Grown ZnO Nanowires: Influence of the Surface Depletion Layer
Arrays of electrodeposited ZnO nanowires (NWs) were used
to illustrate
the dependence of the ZnO visible photoluminescence (PL) emission
on the extension of the surface depletion layer and obtain further
insight into the localization of the related states. With this goal
in mind, three sets of measurements were carried out: (i) analysis
of the PL spectra of ZnO:Cl NWs as a function of their carrier concentration;
(ii) analysis of the PL spectra of ZnO:Cl/ZnO core–shell NWs
as a function of the thickness of their intrinsic ZnO shell; (iii)
in situ analysis of the PL dependence on the polarization of ZnO:Cl
photoelectrodes. The obtained experimental results evidenced that
the yellow and orange emissions from electrodeposited ZnO NWs are
correlated with the extension of the NWs surface depletion region.
This result points out the surface localization of the states at the
origin of these transitions. On the other hand, the green emission
that dominates the visible part of the PL spectra in annealed ZnO
NWs showed no dependence on the surface band bending, thus pointing
toward its origin in the bulk