Die eta-Solarzelle: Ein neues Solarzellenkonzept mit extrem duennem Absorber auf der Basis einer strukturierten TiO_2/CdTe-Grenzflaeche

The concept of a solar cell with an extremely thin absorber (eta) is based on the reduction of transport distances in a solar cell in order to use absorber materials of low electronic quality, i.e. small diffusion lengths. This work presents for the first time an eta-solar cell consisting of a structured pn-heterojunction between a n-type window material and a p-type absorber. The local absorber thickness that determines the maximum transport path is around 150nm. The thesis comprises the screening of different materials such as TiO_2, ZnO and ZnTe and different morphologies regarding scattering properties, surface enlargement, structure and absorption behavior. For the solar cell microporous TiO_2 has been used as a substrate combined with CdTe as absorber material. The conformal coverage of the structured TiO_2-substrates prepared by spraypyrolysis has been achieved by electrodeposition of CdTe. After a post-deposition treatment of the CdTe in CdCl_2-environment, which leads to a recrystallization of the material, the TiO_2 is covered by small crystallites with a size in the order of the local absorber thickness, so that the light generated minority charge carriers do not have to pass any grain boundaries inside the CdTe for collection.SIGLEAvailable from: http://www.diss.fu-berlin.de/2001/102/index.html / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman