Chapter 2 deals with the effect of increasing impurity concentrations on the photoluminescence spectrum.
In sections three and four, experimental methods and results are presented for the systems described in the previous chapters. The apparatus is described for the measurement of transmission, absorptivity, photoluminescence, photo-product spectra and current-voltage characteristics.
The photoluminescence of silicon, Ruthenium dye cells and photosynthesis is found Photoluminescence thesis be consistent with predictions based on the optical absorptivity and induced photocurrent, or photo-product spectra. A novel concept introduced by this thesis is the use of the photo-product spectra to estimate the emissivity and absorptivity used in the Generalized Planck equation.
Solar conversion efficiency predictions based on this equation are applied Photoluminescence thesis these three conversion systems and are found to be consistent with the experimental performance. Specifically, the maximum allowed chemical potentials for the silicon solar cell are found to be 0. The porous silicon solar cell and phototube photodiode results highlight the finding that the chemical potentials predicted from the analysis of photoluminescence are generally much higher than for the actual device.
This is due to the converter configuration and kinetic properties such as resistivity.
In the case of the vacuum photodiode, the configuration of the converter allows for heat and light to simultaneously be converted to work. Although this has been predicted using photoluminescence based models, this thesis presents the first clear demonstration of a synergistic effect in a "hot" electron device.
In hopes of utilizing this effect in a photochemical system, experiments were conducted using the same metal oxide Ag2O as was used as the phototube photodiode absorber. It is found, however, that although the oxide powder reacts at low temperatures, the action of light does not conclusively change the reaction thermodynamics or kinetics.
Silicon is an indirect band gap material and therefore its luminescent properties are poor. For very small dimensions however, as in a nanocrystal of a few nano meter diameter, luminescence becomes strong and blue shifted due quantum confinement. The topic of this thesis is Photoluminescence spectroscopy PL and the spatial and size distribution of silicon nanocrystals.
A main object was to correlate size with their light emitting properties which would be subject to quantum confinement. As a first approach three different oversaturations of silicon atoms in SiO2 were investigated. The size of the nanocrystals and there distance to each other were characterised with an atomic force microscope AFM.
Additionally, the samples were etched with hydro fluoric acid in order to remove the oxide matrix such that individual The Size Distribution and Photoluminescence Spectroscopy.
With this thesis, the details of the measurement concept are to be developed, the photoluminescence based inspection method shall be implemented into the inspection setup and the inspection results of both methods shall be correlated.
This thesis reports the behavior of electrons and holes in photoexcited TiO2 powder under high vacuum conditions. We studied the effect of UV irradiation and different adsorbates, electron acceptors and electron donor molecules, on the perturbation of the band structure of TiO2.
The electron-hole recombination rate in electronically excited TiO2 is influenced by band bending at the TiO2 surface and was studied by photoluminescence PL spectroscopy. In addition, we also employed infrared spectroscopy to qualitatively estimate the surface condition and to quantitatively estimate the amount of adsorbates on the surface.
It was found that continuous UV irradiation at 3. On the other hand, adsorption of an electron acceptor molecule such as O2 induces upward band bending and does not respond completely reversibly upon desorption. Here, we employed NH3 and CO as representatives of slow and fast diffusing molecules, respectively.
Adsorption of NH3 at the outer surface of the TiO2 powder occurs quickly while its distribution in the powder was found to be retarded.Photoluminescence and X-ray Diffraction Analyses of Cadmium Zinc Telluride Crystals by Ramin Jamnejad initiativeblog.com, University of Tehran, A Thesis Submitted in Partial Fulfillment.
photoluminescence specroscopy of cds and gase a thesis submitted to the graduate school of natural and applied sciences of the middle east technical university. Nanowire photoluminescence for photovoltaics Vu, T.T.T.
Published: 31/03/ Document Version The work presented in this thesis has been carried out in the group of Photonics and Semiconductor Nanophysics, at the Department of Applied Physics of the Eindhoven. PHOTOLUMINESCENCE OF INDIUM GALLIUM ARSENIDE QUANTUM DOTS AND DOT CHAINS by Aaron Mitchell Jones A senior thesis submitted to the faculty of Brigham Young University.
Su-Young Cha. thesis on photoluminescence K Chen.
Z Yu. In this thesis, three examples of the application of the photoluminescence technique to indirect semiconductors at low temperatures are presented. Chapter 2 deals with the effect of increasing impurity concentrations on the photoluminescence spectrum.
We present results for the Si:(B,In) system. As the In concentration is increased, we observe quenching of B luminescence.