Optical fiber based spectral response measurement system for multi-junction solar cells

We report an optical fiber based spectral response measurement system for multijunction solar cells. We have also fabricated single junction GaAs cells on GaAS and Ge substrates and measured lighted I-V characteristics. Preliminary quantum efficiency measurements on these devices are also presented. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2200

Coupling between planes and chains in YBa2Cu3O7 : a possible solution for the order parameter controversy

We propose to explain the contradictory experimental evidence about the symmetry of the order parameter in $YBa_{2}Cu_{3}O_{7}$ by taking into account the coupling between planes and chains. This leads to an anticrossing of the plane and chain band. We include an attractive pairing interaction within the planes and a repulsive one between planes and chains, leading to opposite signs for the order parameter on planes and chains, and to nodes of the gap because of the anticrossing. Our model blends s-wave and d-wave features, and provides a natural explanation for all the contradictory experimentsComment: 13 pages, revtex, 2 uucoded figure