0000000000230152
AUTHOR
Margit Zacharias
Optical emission fromSiO2-embedded silicon nanocrystals: A high-pressure Raman and photoluminescence study
We investigate the optical properties of high-quality Si nanocrystals $(\mathrm{NCs})/\mathrm{Si}{\mathrm{O}}_{2}$ multilayers under high hydrostatic pressure with Raman scattering and photoluminescence (PL) measurements. The aim of our study is to shed light on the origin of the optical emission of the Si $\mathrm{NCs}/\mathrm{Si}{\mathrm{O}}_{2}$. The Si NCs were produced by chemical-vapor deposition of Si-rich oxynitride $(\mathrm{SRON})/\mathrm{Si}{\mathrm{O}}_{2}$ multilayers with 5- and 4-nm SRON layer thicknesses on fused silica substrates and subsequent annealing at 1150 \ifmmode^\circ\else\textdegree\fi{}C, which resulted in the precipitation of Si NCs with an average size of 4.1 a…
Luminescence dynamics of hybrid ZnO nanowire/CdSe quantum dot structures
Colloidal CdSe quantum dots (QDs) functionalized with different organic linker molecules are attached to ZnO nanowires (NWs) to investigate the electron transfer dynamics between dots and wires. After linking the quantum dots to the nanowires, the photo-induced electron transfer (PET) from the QDs into the NWs becomes visible in the PL transients by a decrease of dot luminescence decay time. The different recombination paths inside the QDs and the PET process are discussed in the framework of a rate equation model. Photoconductivity studies confirm the electron transfer by demonstrating a strong enhancement of the wire photocurrent under light irradiation into the dot transition. (© 2016 WI…
Electron tunneling from colloidal CdSe quantum dots to ZnO nanowires studied by time-resolved luminescence and photoconductivity experiments
CdSe quantum dots (QDs) with different organic linker molecules are attached to ZnO nanowires (NWs) to study the luminescence dynamics and the electron tunneling from the QDs to the nanowires in time-resolved photoluminescence (PL) and photoconductivity measurements. The PL transients of the QD luminescence indicate two different recombination channels: the direct recombination inside the QD core and the recombination via QD surface defect states. After linking the QDs to the ZnO NW surface, photo-induced electron tunneling from an excited state of the QD into the conduction band of the nanowire becomes visible by a clear decrease of the PL decay time. Efficient electron tunneling is confir…