Synthesis and Structural and Optical Properties of Ga(AsP)Ge and (GaP)Ge Semiconductors Using Interface-Engineered Group IV Platforms.

Epitaxial synthesis of Ga(AsP)Ge alloys on Si(100) substrates is demonstrated using chemical vapor deposition reactions of [DGaN(CH)] with P(GeH) and As(GeH) precursors. These compounds are chosen to promote the formation of GaAsGe and GaPGe building blocks which interlink to produce the desired crystalline product. Ge-rich (GaP)Ge analogues have also been grown with tunable Ge contents up to 90% by reactions of P(GeH) with [DGaN(CH)] under similar deposition protocols.

Rational design of monocrystalline (InP)(y)Ge(5-2y)/Ge/Si(100) semiconductors: synthesis and optical properties.

In this work, we extend our strategy previously developed to synthesize functional, crystalline Si(5-2y)(AlX)y {X = N,P,As} semiconductors to a new class of Ge-III-V hybrid compounds, leading to the creation of (InP)(y)Ge(5-2y) analogues. The compounds are grown directly on Ge-buffered Si(100) substrates using gas source MBE by tuning the interaction between Ge-based P(GeH3)3 precursors and In atoms to yield nanoscale "In-P-Ge3" building blocks, which then confer their molecular structure and composition to form the target solids via complete elimination of H2. The collateral production of reactive germylene (GeH2), via partial decomposition of P(GeH3)3, is achieved by simple adjustment of the deposition conditions, leading to controlled Ge enrichment of the solid product relative to the stoichiometric InPGe3 composition.

Nanosynthesis routes to new tetrahedral crystalline solids: silicon-like Si3AlP.

We introduce a synthetic strategy to access functional semiconductors with general formula A(3)XY (A = IV, X-Y = III-V) representing a new class within the long-sought family of group IV/III-V hybrid compounds. The method is based on molecular precursors that combine purposely designed polar/nonpolar bonding at the nanoscale, potentially allowing precise engineering of structural and optical properties, including lattice dimensions and band structure. In this Article, we demonstrate the feasibility of the proposed strategy by growing a new monocrystalline AlPSi(3) phase on Si substrates via tailored interactions of P(SiH(3))(3) and Al atoms using gas source (GS) MBE.

Anharmonic phonon lifetimes in carbon nanotubes: evidence for a one-dimensional phonon decay bottleneck.

High-resolution Raman spectroscopy is applied to suspended single-walled carbon nanotubes (SWNTs) to elucidate the puzzling differences in the lifetime of the radial breathing mode (RBM) obtained from different experimental techniques. Whereas recent tunneling experiments suggest a room temperature RBM lifetime as long as 10 ns, previous Raman experiments yield lifetimes shorter than 2 ps. The lifetimes obtained in this study are longer than 5 ps-a significant step in the direction of the tunneling results.