The maximum theoretical open circuit voltage of a solar cell is set by its builtin voltage. For amorphous silicon p-i-n cells, the position of the Fermi levels in the p-and ncontact regions are on the order of 0.4 eV and 0.2eV from their respective band edges, limiting the built-in voltage to Eg 0.6eV. We propose replacing the pand n regions by superlattices, in which the Fermi levels in the wi...

the purpose of this paper is the generalization of structure factor for rods by polygon section in two dimensional phononic crystals. if we use the plane wave expansion method (pwe) for the propagation of acoustic waves in 2d phononic crystals, structure factor will be an important quantity. in order to confirm the obtained relations, we have calculated the band structure for xy and z vibration...

zno nanorod was prepared by microwave assisted method. the crystal structure of the nano powders were confirmed by x-ray diffraction analysis and the mean particle size was estimated by the scherrer,s formula .the surface morphology of the nano particles were analyzed by   using sem . the absorption spectrum of the material in the uv-vis range was recorded .the energy band gap of the material w...

The band structure and electronic properties in a series of vinylene-linked heterocyclic conducting polymers are investigated using density functional theory (DFT). In order to accurately calculate electronic band gaps, we utilize hybrid functionals with fully periodic boundary conditions to understand the effect of chemical functionalization on the electronic structure of these materials. The ...