3 research outputs found
Electrical and optical properties of point defects in ZnO thin films
We show that the deposition of ZnO films under varying oxygen partial pressure and annealing conditions allows for the controllable formation of specific defects. Using x-ray diffraction and photoluminescence, we characterize the defects formed and show that these defects are responsible for changes in film carrier density, carrier type, sheet resistivity and mobility
Impact of Different Surface Ligands on the Optical Properties of PbS Quantum Dot Solids
Publisher's PDFThe engineering of quantum dot solids with low defect concentrations
and efficient carrier transport through a ligand strategy is crucial to achieve efficient
quantum dot (QD) optoelectronic devices. Here, we study the consequences of various
surface ligand treatments on the light emission properties of PbS quantum dot films
using 1,3-benzenedithiol (1,3-BDT), 1,2-ethanedithiol (EDT), mercaptocarboxylic acids
(MPA) and ammonium sulfide ((NH4)2S). We first investigate the influence of different
ligand treatments on the inter-dot separation, which mainly determines the conductivity
of the QD films. Then, through a combination of photoluminescence and transient
photoluminescence characterization, we demonstrate that the radiative and non-radiative
recombination mechanisms in the quantum dot films depend critically on the length and
chemical structure of the surface ligands.University of Delaware. Department of Electrical and Computer Engineering.University of Delaware. Department of Materials Science and Engineering