First principles characterization of direct transitions for high efficiency new photovoltaic materials

Some alloys containing a transition metal atom in an III–V host semiconductor show an intermediate half filled band in the middle of the usual semiconductor band gap. The presence of this intermediate band allows to use this material in high efficiency solar cells due to its capability of absorbing low energy photons. In the current work a study of the optoelectronic properties is presented. We mainly focus the work in the obtaining the matrix elements that contribute to direct transitions. We also have analyzed some of the factors on which that process depends. We have also found that some low energy transitions can be found for several points inside the Brillouin zone.