Events

We present a technique capable of producing subwavelength focal spots in planar nonresonant structures not limited to the near-field of the source. The approach combines the diffraction gratings that generate the high-wave-vector-number modes and planar slabs of homogeneous anisotropic metamaterials that propagate these waves and combine them at the subwavelength focal spots.

Density functional calculations have been performed to
elucidate the source of unintentional p-type conductivity in nominally
stoichiometric BaCuChF (Ch = S, Se, Te) wide bandgap semiconductors. Formation
enthalpies and transition levels (activation energies) were found for all
vacancies and antisites, and for some interstitials. Results of this initial
study suggest that of all hole-producing point defects, copper vacancies are
the easiest to form. The formation energy of copper vacancies decreases with increasing