We have used positron annihilation spectroscopy to study vacancy-type defects in strained phosphorus doped Si12xGex layers grown on Si substrates and irradiated with 2-MeV protons. The results show that the dominant defect in the SiGe layer after irradiation is the E center, the vacancy-phosphorus pair. When the sample is annealed at 150–175 °C, the dominant defect species in the SiGe layer cha...

Lithium-rich anti-perovskites (LiRAPs) are a promising family of solid electrolytes, which exhibit ionic conductivities above 10(-3) S cm(-1) at room temperature, among the highest reported values to date. In this work, we investigate the defect chemistry and the associated lithium transport in Li3OCl, a prototypical LiRAP, using ab initio density functional theory (DFT) calculations and classi...

We describe a two-step-size tapered structure with one defect pair that can markedly enhance the coupling efficiency at the entrance and exit terminals of a planar photonic crystal (PPC) waveguide. PPC waveguides are composed of circular dielectric rods set in two-dimensional square lattices. On the basis of our simulations, we found that the optimized scheme maximizes the power transmission ab...

This article describes technique to make the sectional impression of the maxillectomy defect of a patient with the reduced mouth opening. The cast generated after pouring the impression is duplicated twice to fabricate the defect component and the palatal base-plate component separately. Both the components were then oriented and attached with the help of a pair of the magnets. This magnet reta...

The origin of photoluminescence in copper indium sulfide (CIS) quantum dots (Qdots) has previously been ascribed to a donor– acceptor pair (DAP) recombination, with a crystal lattice defect implicated as the origin of the donor state. In this study, electron energy-loss spectroscopy (EELS) was used to observe defect-rich compositional domains within individual CIS Qdots, supporting a model of d...

The origin of photoluminescence in copper indium sulfide (CIS) quantum dots (Qdots) has previously been ascribed to a donor-acceptor pair (DAP) recombination, with a crystal lattice defect implicated as the origin of the donor state. In this study, electron energy-loss spectroscopy (EELS) was used to observe defect-rich compositional domains within individual CIS Qdots, supporting a model of de...

Metastable arsenic-antisite{gallium-antisite pair in GaAs has been studied using self-consistent, parameter-free total energy methods. The metastability of this defect is similar to that of the isolated arsenic-antisite. The anti-structure pair has ionization levels in the band gap in the metastable connguration, unlike the isolated arsenic-antisite. These ionization levels enable absorption of...

A new set of software development methodologies has become prevalent in previous years, commonly known as Agile techniques. Pair programming (an activity from agile techniques)where two programmers work on the same module at one computer; with one programmer takes responsibilities of writing the actual code and the other one takes the responsibility for the monitoring of strategies, designing a...