Comparing resonant photon tunneling via cavity modes and Tamm plasmon polariton modes in metal-coated Bragg mirrors

Resonant photon tunneling was investigated experimentally in multilayer structures containing a high-contrast (TiO2/SiO2) Bragg mirror capped with a semitransparent gold film. Transmission via a fundamental cavity resonance was compared with transmission via the Tamm plasmon polariton resonance that appears at the interface between a metal film and a one-dimensional photonic bandgap structure. The Tamm-plasmon-mediated transmission exhibits a smaller dependence on the angle and polarization of the incident light for similar values of peak transmission, resonance wavelength, and finesse. Implications for transparent electrical contacts based on resonant tunneling structures are discussed

Selective Growth of B- and C-Doped SiGe Layers in Unprocessed and Recessed Si Openings for p-type Metal-Oxide-Semiconductor Field-Effect Transistors Application

This work presents the pattern dependency of the selective epitaxial growth of boron- and carbon-doped SiGe layers in recessed and unprocessed openings. The layer profile is dependent on deposition time, chip layout, and growth parameters. Carbon and boron doping compensates for the strain in SiGe layers, and when both dopants are introduced, the strain reduction is additive. The incorporation of boron and carbon in the SiGe matrix is a competitive action. The concentration of carbon decreases, whereas the boron amount increases in SiGe layers with higher Ge content. In recessed openings, the Ge content is independent of the recess depth. The strain amount in the grown layers is graded vertically, which is due to the thickness of the epilayer exceeding the critical thickness

Emission Mössbauer spectroscopy study of fluence dependence of paramagnetic relaxation in Mn/Fe implanted ZnO

Emission Mössbauer Spectroscopy following the implantation of radioactive precursor isotope $^{57}$Mn$^{+}$ (T$_{1/2}$= 1.5 min) into ZnO single crystals at ISOLDE/CERN shows that a large fraction of $^{57}$Fe atoms produced in the $^{57}$Mn beta decay is created as paramagnetic Fe$^{3+}$ with relatively long spin-lattice relaxation times. Here we report on ZnO pre-implanted with $^{56}$Fe to fluences of 2×10$^{13}$, 5×10$^{13}$ and 8 × 10$^{13}$ ions/cm2 in order to investigate the dependence of the paramagnetic relaxation rate of Fe$^{3+}$ on fluence. The spectra are dominated by magnetic features displaying paramagnetic relaxation effects. The extracted spin-lattice relaxation rates show a slight increase with increasing ion fluence at corresponding temperatures and the area fraction of $^{3+}$ at room temperature reaches a maximum contribution of 80(3)% in the studied fluence range

Lattice sites, charge states and spin–lattice relaxation of Fe ions in 57Mn+ implanted GaN and AlN

The lattice sites, valence states, resulting magnetic behaviour and spin–lattice relaxation of Fe ions in GaN and AlN were investigated by emission Mössbauer spectroscopy following the implantation of radioactive $^{57}Mn^+$ ions at ISOLDE/CERN. Angle dependent measurements performed at room temperature on the 14.4 keV γ-rays from the 57Fe Mössbauer state (populated from the $^{57}$Mn $β ^−$ decay) reveal that the majority of the Fe ions are in the 2+ valence state nearly substituting the Ga and Al cations, and/or associated with vacancy type defects. Emission Mössbauer spectroscopy experiments conducted over a temperature range of 100–800 K show the presence of magnetically split sextets in the “wings” of the spectra for both materials. The temperature dependence of the sextets relates these spectral features to paramagnetic $Fe^{3+}$ with rather slow spin–lattice relaxation rates which follow a $T^2$ temperature dependence characteristic of a two-phonon Raman process

57^{57}Fe emission Mössbauer spectroscopy following dilute implantation of 57Mn^{57} Mn into In 2O3_2O_3

Emission Mössbauer spectroscopy has been utilised to characterize dilute $^57$Fe impurities in In $_2O_3$ following implantation of $^57$Mn ($T_{1/2}$ = 1.5 min.) at the ISOLDE facility at CERN. From stoichiometry considerations, one would expect Fe to adopt the valence state 3 + , substituting In $^{3+}$, however the spectra are dominated by spectral lines due to paramagnetic Fe$^{2+}$. Using first principle calculations in the framework of density functional theory (DFT), the density of states of dilute Fe and the hyperfine parameters have been determined. The hybridization between the 3d-band of Fe and the 2p band of oxygen induces a spin-polarized hole on the O site close to the Fe site, which is found to be the cause of the Fe$^{2+}$ state in In $_2O_3$. Comparison of experimental data to calculated hyperfine parameters suggests that Fe predominantly enters the 8b site rather than the 24d site of the cation site in the Bixbyite structure of In $_2O_3$. A gradual transition from an amorphous to a crystalline state is observed with increasing implantation/annealing temperature