The epitaxial lift-off (ELO) technique can be used to separate a III-V solar cell structure from its underlying GaAs or Ge substrate. ELO from 4-inch Ge wafers is shown and 2-inch GaAs wafer reuse after lift-off is demonstrated without degradation in performance of the subsequent thin-film GaAs solar cells that were retrieved from it. Since a basic wet chemical smoothing etch procedure appeared insufficient to remove all the surface contamination, wafer re-preparation is done by a chemo-mechanical polishing procedure.

The novel neutral and anionic gallium clusters Ga 10 R′ 6 and [Ga 10 R* 6 ]as well as [Ga 13 R* 6 ]are obtained by reaction of "GaI", prepared sonochemically from gallium and iodine, with Li(THF) 3 R′ (R′ ) Si(SiMe 3 ) 3 ) hypersilyl) and Na(THF) 2 R* (R* ) SitBu 3 ) supersilyl), respectively. Both of the Ga 10 clusters may be considered as conjuncto clusters consisting of two edge-sharing octahedrons. In Ga 10 R′ 6 , these contain a Ga 4 R′ 4 and a Ga 2 R′ 2 unit, and in [Ga 10 R* 6 ] -, they contain two Ga 3 R* 3 units. In addition to the syntheses and X-ray structure analyses of these three clusters, some hypersilylgallium halides are described, namely the [Li(THF) 2 ] + and [Li(THF) 3 ] + salts of [R′GaI 3 ]as well as the [Li(THF) 2 ] + salts of [R′ 2 Ga 2 Br 4 ] 2and [R′ 2 Ga 2 I 4 ] 2-.

No abstract

Keywords: Bismuth / Lithium / Sodium / Silicon / Cluster compounds The reaction of bismuth trihalides with the bulky alkali metal silanides [(THF) 3 LiSi(SiMe 3 ) 3 ] and [(THF) 2 NaSi(CMe 3 ) 3 ] affords the cyclotetrabismuthanes (RBi) 4 1 and 3, the alkali metal bismuthanides [Li(THF) 4 ][Bi{Si(SiMe 3 ) 3 } 2 ](2) and Na(THF) 3 [Bi{Si(CMe 3 ) 3 }] 2 (4) and the bismuthanediide Na 3 (THF) 14 [Na 21 {BiSi(CMe 3 ) 3 } 12 ] (5). Compound 2 features a two-coordinate bismuth atom. The core of 5 is a Bi 12 icosa-

The 3G30-Advanced, AZUR SPACE's latest qualified solar cell product, provides highest end-of-life efficiencies in space. The cell reaches 27.8% at a fluence of 5 E14 cm -2 and 26.5% at a fluence of 1 E15 cm -2 1 MeV electrons. The cell mass can be reduced to a minimum by substrate thinning, the cell cost can be reduced by implementation of large area configurations and even higher radiation hardness can be achieved by using AZUR's proprietary 3G30-1E16+ design. Various configurations are currently in production. The increasing demand for cells suited for LEO applications, made AZUR to develop a novel upright metamorphic triple junction solar cell with a BOL efficiency of 31% designed for a fluence of 1 E14 cm -2 1 MeV electrons. This cell design is already in production. AZUR's next generation product 4G32 comprises an upright metamorphic 4-junction device with 28.5% EOL (1 E15 cm -2 1 MeV electrons) efficiency. Hence, the 4G32 even surpasses the EOL efficiency of the lattice-matched 3-junction cell 3G30-Advanced. It utilizes the excess current of the Ge subcell by a metamorphic cell concept and a fourth junction added to the stack. This cell will be qualified by mid-2017. This paper summarizes the results and achievements for various 3G and 4G solar cell products from AZUR SPACE, including radiation hardness and cell formats.

Trigonal bipyramidal clusters based on iron carbonyl and gallandiyl derivatives are described. Two types of cluster cores are shown right. a) The Ga3−xCOxFe2 core (Ga3Fe2 shown) is derived from Fe2(CO)9 by the replacement of all, two, or one of the bridging CO ligands with (Me3Si)3SiGa. b) The Ga2Fe3 core is understood as a closo‐type cluster following Wade's rules, whereas for a) a classical description is valid. All clusters may be obtained from the reaction of [{Ga(Cl)Si(SiMe3)3}4] with the iron carbonylates Na2Fe(CO)4, Na2Fe2(CO)8 and Na2Fe3(CO)11.

A cage comprising four gallium and four chlorine atoms (shown on the right) is the characteristic feature of the first dimeric digallane 1 (R = Si(SiMe3)3) having two different substituents. It is synthesized together with the tetrasilyl‐substituted digallane 2 from Ga[GaCl4] and LiSi(SiMe3)3(THF)3.

The diaminopropane derivative Me 2 C[CH 2 N(H)SiMe 3 ] 2 is metallated with n-butyllithium and lithium tetrahydridoaluminate to obtain Me 2 C[CH 2 N(Li)SiMe 3 ] 2 and Me 2 C[CH 2 N(Li)Si-Me 3 ][CH 2 N(AlH 2 )SiMe 3 ], respectively. Both compounds exhibit a central eight-membered ring, Li 4 N 4 or Li 2 Al 2 N 4 . Me 2 C[CH 2 N(Li)-SiMe 3 ] 2 reacts with Ga 2 Cl 4 · 2dioxane under formation of the cor- EinleitungLithiumamide finden vielfache Anwendung in der Synthesechemie. Die Strukturen von einfachen Verbindungen LiNRRЈ wurden sowohl im Festkörper als auch in Lösung eingehend untersucht [1Ϫ3]. Oligofunktionelle Amine sollten die Ausbildung neuartiger Strukturen der lithiierten Spezies ermöglichen, da hier durch das Amingerüst geometrische Zwänge auferlegt werden. In den letzten Jahren gelang die strukturelle Untersuchung einer Reihe von Trilithiotriaminen [4,5]. Die zweifach lithiierten Diamine mit Ausnahme der 1,1-Bisaminosilanderivate wie z.B. A [6, 7] und 1,2-Dilithiohydrazide [8,9] wurden bislang weniger eingehend bearbeitet. Ausgewählte Beispiele sind N,NЈ-Dilithio-diphenylethylendiamin [10], das als monomeres HMPA-Addukt vorliegt (B), das dimere N,NЈ-Dilithiobis(2,6-diisopropylphenyl)ethylendiamins C mit "Leiter-Ring vor. Me 2 C[CH 2 N(Li)SiMe 3 ] 2 reagiert mit Ga 2 Cl 4 · 2Dioxan u.a. zum entsprechenden Tetra(amino)digallan. Dieses liegt im Unterschied zum dimeren tetraalkoxysubstituierten Digallan, Ga 4 O t Bu 8 , monomer vor. Alle Verbindungen wurden mittels Einkristall-Röntgenstrukturanalyse untersucht.responding tetra(amino)digallane. This is monomeric, in contrast to a dimeric tetraalkoxy-substituted digallane, Ga 4 O t Bu 8 . All compounds were characterized by single crystal X-ray crystallography.