High-quality fully strained ${\mathrm{Si}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ge}}_{\mathit{x}}$ layers with 0%x22% grown on Si(100) by rapid thermal chemical vapor deposition have been analyzed photoluminescence spectroscopy. We report a well-resolved near-band-gap excitonic transition observed in SiGe layers. These transitions make it possible to determine directly the fundamental band gap of such alloys. The results show that high surface recombination very thin films prevents...

InAs nanostructures were grown on In0.52Al0.48As alloy lattice matched InP(001) substrates by molecular beam epitaxy using specific growth parameters in order to improve island self-organization. We show how the change surface reconstruction via temperature from (2×4) (2×1) and/or use of InAlAs initial buffer treatments shape homogeneity (either as quantum wires or dots). Differences and carrier confinement are shown atomic force microscopy photoluminescence measurements, respectively. point...

ZnO nanowires grown in liquid phase are considered as promising building blocks for a wide variety of optical and electrical devices. However, their structural morphology is still limited by the lack understanding growth mechanisms. We have systematically investigated effects orientation polarity monocrystals acting substrates on formation mechanisms chemical bath deposition. Under identical conditions, two-dimensional layers develop nonpolar m- a-plane monocrystals. In contrast, form...

We show how the height dispersion of self-organized InAs/InP(001) quantum islands emitting at 1.55 μm was reduced by optimizing epitaxial growth parameters. Low obtained when InAs deposit thickness much greater than critical for two-dimensional/three-dimensional mode transition, and adatom surface diffusion favored increasing temperature or reducing arsenic pressure during growth. When these conditions are not respected, multicomponent photoluminescence spectrum is explained through common...

An atomic force microscopy (AFM) tip has been used to manipulate silicon nanocrystals deposited by low-pressure chemical vapour deposition on thermally oxidized p-type Si wafer. Three nanomanipulation methods are presented. The first one catches a nanocrystal with the AFM and deposits it elsewhere: is as an electrostatic 'nano-crane'. second simultaneously manipulates set of in order draw well-defined unidimensional lines: 'nano-broom'. third individual precision about 10 nm using both...

The positions of the acceptor level vanadium in GaAs, GaP, and InP are estimated. This is found to be at about Ec−0.14 eV GaAs Ec−0.8 GaP. It above conduction band edge InP. These three hosts agreement with trends proposed by Ledebo Ridley. finding a very high does not allow explain semi-insulating behavior GaAs:V. Other possible compensating centers considered.

Mastering the structural ordering of ZnO seed layers by sol–gel process in terms ultrathin thickness (i.e, <10 nm), strong c-axis texture, low mosaicity, porosity, and roughness is a critical challenge for formation well-ordered nanowires solution. The effects solution concentration, withdrawal speed, annealing on mechanisms deposited single dip are revealed. size density primary clusters sol found to govern evolution film nanoparticle average diameter through concentration. Landau–Levich...

The characteristics of a single electron trap related to the iron deep level acceptor have been determined for first time by DLTS techniques in indium phosphide. An activation energy 0.63 eV and capture cross-section 3.5×10−14 cm2 measured. presence this nominally undoped samples shows that can be an important residual impurity InP.

We have studied the influence of surface properties on nucleation and growth silicon quantum dots (Si-QDs) deposited by low-pressure chemical vapor deposition (LPCVD). First, effect siloxane groups (Si-O-Si) strain at layer, characterized Fourier transform infrared (FTIR) spectroscopy, is studied. evidenced an increase Si-QD with in substrate layer. Second, strongly depends silanol group (Si-OH) density. This density, controlled thermal treatments, measured multiple internal reflexion (MIR)...

Carrier confinement in InAs quantum dashes (QDas) grown on InP(001) is investigated both experimentally and theoretically. The aim of these studies to reconstruct the electronic structure QDas. QDas with low size dispersion are achieved by improving growth conditions. Optical transitions between ground excited states studied continuous-wave-photoluminescence photoluminescence-excitation experiments at temperature. We also report infrared spectroscopy conduction-band intersubband transitions....

A complete study based on advanced atomic force microscopy electrical mode called scanning spreading resistance (SSRM) is carried out a series of samples zinc oxide (ZnO) nanowires grown by chemical bath deposition with different doping concentrations using gallium (Ga). The concentration free charge carriers determined through SSRM signal calibration specific molecular beam epitaxy-grown multilayer structure variation in each layer electrically active Ga ranges from 1 × 1017 to 7 1020...

A solid iron source was used in a limited reaction processing (LRP) system to deposit beta -FeSi/sub 2/ selectively and epitaxially onto patterned silicon wafers. The layers of stoichiometric composition show two main photoluminescence emission bands (at 0.79 0.94 eV) an extrinsic conductivity energy level 0.10 eV). Selective mostly epitaxial deposition semiconducting disilicide has been obtained by LRP Fe producing chlorinated metal species. films are formed columns oriented with the...

We have used low temperature photoluminescence measurements in order to quantify the impact of strain effect on Si indirect band gap 9 nm thick tensely strained silicon insulator layers. A redshift transverse optical phonon excitonic recombination layer was evidenced as is increased. Band shrinkages Δ direction equal 130±3 meV, 184±3 and 239±3 meV were obtained for 0.87±0.03%, 1.22±0.05%, 1.54±0.06% values. These measured transitions are good agreement with calculated

The size of silicon quantum dots (Si QDs) embedded in nitride (SiNx) has been controlled by varying the total pressure plasma-enhanced chemical vapor deposition (PECVD) reactor. This is evidenced transmission electron microscopy and results a shift light emission peak dots. We show that luminescence our structures attributed to confinement effect. These findings give strong indication quality (density distribution) Si QDs can be improved optimizing parameters which opens route fabrication an...

We have investigated the effect of misorientated InP(001) substrates on optical properties InAs quantum islands (QIs) grown by molecular-beam epitaxy in Stranski–Krastanow regime. Detailed temperature-dependent photoluminescence (PL), excitation density PL, and polarization (PPL) are studied. PPL shows a high degree linear (near 40%) for nominally oriented substrate n with 2° off miscut angle toward [110] direction (2° F), while it is near 15% towards [010] B), indicating growth wires...

Photoluminescence (PL) and photoluminescence excitation (PLE) experiments are carried out in order to study the electronics states self-assembled InAs quantum islands (QI's) fabricated on InP(001) substrate by solid source molecular-beam epitaxy using Stranski-Krastanov growth mode. The conditions of QI's have been optimized (high temperature, low arsenic pressure rate) minimize island size dispersion. low-temperature (8 K) PL spectrum InAs/InP(001) is characterized multicomponent...

A simple and low cost technological approach for the straining of thin crystalline silicon (Si) films using porous (PS) as stress generating nanomaterial is reported. Structural analysis PS∕Si structures performed by transmission electron microscopy. Raman scattering spectroscopy used evaluation strain values in strained Si films. Depending on thickness films, maximum are found to be a range from 1% 1.4%. Various modifications electronic properties observed photoluminescence spectroscopy....

Abstract Steady‐state and time‐resolved photoluminescence of silicon nanoparticles dispersed in low‐polar liquids at above room temperature is studied. The roles as well mechanisms responsible for their temperature‐dependent are discussed. thermal sensitivity the estimated application nanothermometers proposed. magnified image (© 2013 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)