الفهرس 
Theoritical backgroundOnly 14 pages are availabe for public view
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Abstract
Solar cells have poor spectral response (SR) to short-wavelength
light and the sub-band-gap photons (IR) can’t be absorbed inside the solar
cell and therefore can’t contribute to the generation of electron—hole pairs.
The application of a luminescent down-shifting (LDS) layer has been
proposed as a method for improving the poor spectral response (SR) of solar
cells to short-wavelengths light. The LDS layer absorbs photons, typically in
the 300—500 nm range, and re-emits them at a longer wavelength where the
photovoltaic (PV) device exhibits a significantly better response.
The up-conversion luminescent layer has been proposed as a method
to partially convert the sub-band-gap photons (IR) to higher photon
energies. The up converted photons can then be absorbed inside the solar
cell and therefore contribute to the generation of additional electron—hole
pairs, potentially leading to significantly higher conversion solar cell
efficiencies.
This work aiming to prepare a thin film layer containing both down
shifting active centers and up converter active centers DUCL (Down and
Up Conversion Layer) then deposit this film over the surface of the solar
cell to enhance its efficiency.
CdS was chosen as fluorescence material for the down shifting
conversion and Er3~ was chosen as an active centre for the up conversion.
CdS and Er3~ ions are embedded in silica (host material) using sol gel
technique.
The present work contains four main chapters in addition to lists of
figures, tables and references.