Search

Dye sensitized solar cells were fabricated using ZnO nanostructured photoelectrodes sensitized with N-719 or Rose Bengal dyes. We assessed the device performance as a function of the sensitization time and found a dependence on time for the N-719 and no significant changes for the Rose Bengal. Furthermore, we observe that the structure of the N-719 molecule beneficial for sensitization of TiO2 may lead to the degradation of the ZnO crystals and a growth of an amorphous shell limiting dye performance in the cells.

High-resolution X-ray di ractometer was used to study structural quality, lattice parameters and mis t strain in p-ZnTe/n-CdTe heterojunctions grown by the molecular-beam epitaxy technique on two di erent (001)-oriented substrates of GaAs and CdTe. The X-ray di ractometer results indicate that the CdTe layers, grown on lattice mismatched GaAs substrate, are partially relaxed, by the formation of mis t dislocations at the interface, and display residual vertical strain of the order of 10−4. The presence of threading dislocations in the layers e ectively limits the e ciency of solar energy conversion in the investigated heterojunctions. Homoepitaxially grown CdTe layers, of much better structural quality, display unexpected compressive strain in the layers and the relaxed lattice parameter larger than that of the substrate. Possible reasons for the formation of that unusual strain are discussed.