More to read in physica status solidi (a) - Amazon S3 · low-spin states and the transport...
2
More to read in physica status solidi (a) S. Hébert, W. Kobayashi, H. Muguerra, Y. Bréard, N. Raghavendra, F. Gascoin, E. Guilmeau, and A. Maignan From oxides to selenides and sulfides: The richness of the CdI 2 type crystallographic structure for thermoelectric properties [Feature Article] Phys. Status Solidi A 210(1), 69–81 (2013), DOI 10.1002/pssa.201228505 The CdI 2 type crystallographic structure is a very rich family in which oxides and non-oxide materials can be synthesized. For oxides, Na x CoO 2 has already been found to be a promising p- type thermoelectric material. Hébert et al. analyze the thermoelectric properties of misfit cobalt oxides, showing the relationship between this layered structure which stabilizes Co 3+ and Co 4+ in low-spin states and the transport properties. By changing the separating block layer, or by modifying oxides into selenides or sulfides, it is possible to strongly modify the transport properties. Furthermore, the interesting thermoelectric properties of sulfides and selenides, with ZT up to 0.5 at 800 K, and the differences between their properties and those of oxides, are shown. V. N. Jmerik, E. V. Lutsenko, and S. V. Ivanov Plasma-assisted molecular beam epitaxy of AlGaN heterostructures for deep-ultraviolet optically pumped lasers [Feature Article] Phys. Status Solidi A 210(3), 439–450 (2013), DOI 10.1002/pssa.201300006 Plasma-assisted molecular beam epitaxy of Al x Ga 1–x N-based quantum well (QW) structures with high Al content (up to 50% in the QW) grown directly on c-sapphire is described by Jmerik et al. Special attention is paid to the growth conditions of (i) AlN nucleation layers with suppressed generation of threading dislocations (TDs), (ii) atomically-smooth AlN buffer layers with strained GaN insertions and AlGaN/AlN superlattice to decrease TD density, (iii) cladding and waveguide AlGaN layers with atomically-smooth droplet-free morphology and QW region fabricated by sub- monolayer digital alloying. These QW structures demonstrate optically-pumped lasing within the deep-UV wavelength range with threshold power density below 600 kW/cm 2 (at 289 nm). Ping Chen, Mingsheng Qin, Haijie Chen, Chongying Yang, Yaoming Wang, and Fuqiang Huang Cr incorporation in CuGaS 2 chalcopyrite: A new intermediate-band photovoltaic material with wide-spectrum solar absorption Phys. Status Solidi A 210(6), 1098–1102 (2013), DOI 10.1002/pssa.201228721 CuGa 1–x Cr x S 2 semiconductor was investigated by the self-consistent many-body GW approach and further confirmed by experimental results. The Cr dopant introduced a partially occupied intermediate band (IB), and the density-of-states analysis indicates that the electron transfer between impurities and host lattice would suppress non-radiative recombination. CuGa 1–x Cr x S 2 was synthesized by a high-temperature solid-state reaction. Two additional absorption responses were directly observed in the UV–Vis–NIR absorption spectrum. Further photocatalytic investigations verified that the IB absorptions could produce highly mobile electrons and holes to degrade dyes. This material leads to lower-energy photon absorption, which could be promising for high- efficiency solar cells. Dieter Weller, Oleksandr Mosendz, Gregory Parker, Simone Pisana, and Tiffany S. Santos L10 FePtX–Y media for heat-assisted magnetic recording [Review Article] Phys. Status Solidi A 210(7), 1245–1260 (2013), DOI 10.1002/pssa.201329106 This Review Article discusses highly chemically ordered L1 0 FePtX–Y nano-granular films with high perpendicular magnetic anisotropy as key media approaches for future heat-assisted magnetic recording. They are sputter-deposited at about 600 °C and grown on well oriented MgO(002) texture layers. X = Ag and Cu reduce the deposition and Curie temperature. Y = carbon or other segregants are used to optimize grain size, shape and dispersion, which together with thermal conductivity are critical to extend the areal density in future magnetic recording to 1.5–5 Tb/in 2 .
Transcript of More to read in physica status solidi (a) - Amazon S3 · low-spin states and the transport...
More to read in physica status solidi (a)
S. Hébert, W. Kobayashi, H. Muguerra, Y. Bréard, N. Raghavendra, F. Gascoin, E. Guilmeau, and A. Maignan From oxides to selenides and sulfides: The richness of the CdI2 type crystallographic structure for thermoelectric properties [Feature Article] Phys. Status Solidi A 210(1), 69–81 (2013), DOI 10.1002/pssa.201228505 The CdI2 type crystallographic structure is a very rich family in which oxides and non-oxide materials can be synthesized. For oxides, NaxCoO2 has already been found to be a promising p-type thermoelectric material. Hébert et al. analyze the thermoelectric properties of misfit cobalt oxides, showing the relationship between this layered structure which stabilizes Co3+ and Co4+ in low-spin states and the transport properties. By changing the separating block layer, or by modifying oxides into selenides or sulfides, it is possible to strongly modify the transport properties. Furthermore, the interesting thermoelectric properties of sulfides and selenides, with ZT up to 0.5 at 800 K, and the differences between their properties and those of oxides, are shown.
V. N. Jmerik, E. V. Lutsenko, and S. V. Ivanov Plasma-assisted molecular beam epitaxy of AlGaN heterostructures for deep-ultraviolet optically pumped lasers [Feature Article] Phys. Status Solidi A 210(3), 439–450 (2013), DOI 10.1002/pssa.201300006 Plasma-assisted molecular beam epitaxy of AlxGa1–xN-based quantum well (QW) structures with high Al content (up to 50% in the QW) grown directly on c-sapphire is described by Jmerik et al. Special attention is paid to the growth conditions of (i) AlN nucleation layers with suppressed generation of threading dislocations (TDs), (ii) atomically-smooth AlN buffer layers with strained GaN insertions and AlGaN/AlN superlattice to decrease TD density, (iii) cladding and waveguide AlGaN layers with atomically-smooth droplet-free morphology and QW region fabricated by sub-monolayer digital alloying. These QW structures demonstrate optically-pumped lasing within the deep-UV wavelength range with threshold power density below 600 kW/cm2 (at 289 nm).
Ping Chen, Mingsheng Qin, Haijie Chen, Chongying Yang, Yaoming Wang, and Fuqiang Huang Cr incorporation in CuGaS2 chalcopyrite: A new intermediate-band photovoltaic material with wide-spectrum solar absorption Phys. Status Solidi A 210(6), 1098–1102 (2013), DOI 10.1002/pssa.201228721 CuGa1–xCrxS2 semiconductor was investigated by the self-consistent many-body GW approach and further confirmed by experimental results. The Cr dopant introduced a partially occupied intermediate band (IB), and the density-of-states analysis indicates that the electron transfer between impurities and host lattice would suppress non-radiative recombination. CuGa1–xCrxS2 was synthesized by a high-temperature solid-state reaction. Two additional absorption responses were directly observed in the UV–Vis–NIR absorption spectrum. Further photocatalytic investigations verified that the IB absorptions could produce highly mobile electrons and holes to degrade dyes. This material leads to lower-energy photon absorption, which could be promising for high-efficiency solar cells.
Dieter Weller, Oleksandr Mosendz, Gregory Parker, Simone Pisana, and Tiffany S. Santos L10 FePtX–Y media for heat-assisted magnetic recording [Review Article] Phys. Status Solidi A 210(7), 1245–1260 (2013), DOI 10.1002/pssa.201329106 This Review Article discusses highly chemically ordered L10 FePtX–Y nano-granular films with high perpendicular magnetic anisotropy as key media approaches for future heat-assisted magnetic recording. They are sputter-deposited at about 600 °C and grown on well oriented MgO(002) texture layers. X = Ag and Cu reduce the deposition and Curie temperature. Y = carbon or other segregants are used to optimize grain size, shape and dispersion, which together with thermal conductivity are critical to extend the areal density in future magnetic recording to 1.5–5 Tb⁄in2.
Simone Hofmann, Mauro Furno, Björn Lüssem, Karl Leo, and Malte C. Gather Investigation of triplet harvesting and outcoupling efficiency in highly efficient two-color hybrid white organic light-emitting diodes [Advanced Materials Physics] Phys. Status Solidi A 210(8), 1467– (2013), DOI 10.1002/pssa.201329107 Singlet and triplet transfer processes are studied in white triplet harvesting organic light-emitting diodes, comprising fluorescent and phosphorescent emitter molecules. The CIE coordinates of these devices can be adjusted over a wide range by varying the distance between exciton generation and triplet harvesting zone. Optical modeling of the electromagnetic field and a comparison to the position of the emitters confirms that the devices operate close to the optical optimum.
Aleksei Anopchenko, Alessandro Marconi, Fabrizio Sgrignuoli, Laura Cattoni, Andrea Tengattini, Georg Pucker, Yoann Jestin, and Lorenzo Pavesi Electroluminescent devices based on nanosilicon multilayer structures [Invited Article] Phys. Status Solidi A 210(8), 1525– (2013), DOI 10.1002/pssa.201200957 Anopchenko et al. report on the development of size-controlled multilayered ensembles of silicon nanocrystals for efficient light emitting devices. The ensembles of silicon nanocrystals embedded in silicon dioxide are grown by chemical vapour deposition methods and by using standard microelectronic processes. The formation of nanocrystals is monitored by several analytical techniques. Novel light emitting device architectures of nanocrystal ensembles which improve electrical injection and light emission are described. Charge tunnelling in nanosilicon superlattices, light emission efficiency under direct and alternating current injection, and device stability are discussed.
D. Takeuchi, S. Koizumi, T. Makino, H. Kato, M. Ogura, H. Ohashi, H. Okushi, and S. Yamasaki Negative electron affinity of diamond and its application to high voltage vacuum power switches [Feature Article] Phys. Status Solidi A 210(10), 1961– (2013), DOI 10.1002/pssa.201300385 Compact high-voltage power switches are highly desirable for intelligent power grids with renewable energy sources. A compact high-voltage switch using electron emitters, which cannot be realized with conventional semiconductor devices, has been proposed by Takeuchi et al. utilizing the insulating effect of a vacuum. The first result of 10 kV switching at room temperature using a diamond PIN junction electron emitter is presented. A power transmission efficiency of 73% was realized. For over 100 kV, an efficiency >99.92% could be designed. Hence, the vacuum switches are confirmed to be promising, compact (ultra) high voltage switches.
R. Tenne, R. Rosentsveig and A. Zak Inorganic nanotubes and fullerene-like nanoparticles: synthesis, mechanical-properties and applications [Invited Article] Phys. Status Solidi A 210(11), 2253–2258 (2013), DOI 10.1002/pssa.201329309 With their high crystalline perfection and mechanical robustness, inorganic nanotubes and nanowires – in particular multiwall WS2 nanotubes which are synthesized in large amounts – were found to be very suitable for reinforcing a variety of polymer nanocomposites at low concentrations (<2 wt%). Such nanocomposites exhibit favorable properties making them suitable for a wide range of commercial applications in the aerospace, defense, automotive, sport, medical-technology and other industries. A summary of recently obtained results is reported in a concise minireview by Tenne et al.
