Growth model and structure evolution of Ag layers deposited on Ge films

• Arkadiusz Ciesielski,
• Lukasz Skowronski,
• Ewa Górecka,
• Jakub Kierdaszuk and
• Tomasz Szoplik

Beilstein J. Nanotechnol. 2018, 9, 66–76, doi:10.3762/bjnano.9.9

• ) and X-ray diffraction (XRD) measurements proved that segregation of germanium into the surface of the silver film is a result of the gradient growth of silver crystals. The free energy of Ge atoms is reduced by their migration from boundaries of larger grains at the Ag/SiO2 interface to boundaries of

• ongoing recrystallization. The Raman spectra of the Ge wetted Ag films were measured immediately after deposition and ten days later and demonstrated that the Ge atoms at the Ag grain boundaries form clusters of a few atoms where the Ge–Ge bonds are still present. Keywords: germanium; segregation; self

• 10 nm Ag layer on a sapphire substrate at room temperature with a 1 nm germanium wetting film [18]. Recently, it was observed that the germanium atoms, which form the nucleation film, efficiently segregate [21] through the silver structure towards the surface [22][23], which results in additional

Intercalation of Si between MoS₂ layers

• Rik van Bremen,
• Qirong Yao,
• Soumya Banerjee,
• Deniz Cakir,
• Nuri Oncel and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2017, 8, 1952–1960, doi:10.3762/bjnano.8.196

• silicon and germanium were performed by Takeda and Shiraishi in 1994 [5]. These authors pointed out that two-dimensional silicon and germanium are not planar but buckled, i.e., the two sub-lattices of the honeycomb lattice are displaced with respect to each other in a direction normal to the two

• monolayer of MoS2 [23]. This means that MoS2 has no states near the Fermi level and therefore hybridization with the energy bands of silicene near the Fermi level cannot occur. Recently, germanene, a 2D allotrope of germanium [24][25][26][27][28], has already been successfully grown on MoS2 [29]. Chiappe et

Coexistence of strongly buckled germanene phases on Al(111)

• Weimin Wang and
• Roger I. G. Uhrberg

Beilstein J. Nanotechnol. 2017, 8, 1946–1951, doi:10.3762/bjnano.8.195

• Weimin Wang Roger I. G. Uhrberg Department of Physics, Chemistry, and Biology, Linköping University, S-581 83 Linköping, Sweden 10.3762/bjnano.8.195 Abstract We report a study of structural and electronic properties of a germanium layer on Al(111) using scanning tunneling microscopy (STM), low

• energy electron diffraction and core-level photoelectron spectroscopy. Experimental results show that a germanium layer can be formed at a relatively high substrate temperature showing either (3×3) or (√7×√7)R±19.1° reconstructions. First-principles calculations based on density functional theory suggest

Group-13 and group-15 doping of germanane

• Nicholas D. Cultrara,
• Maxx Q. Arguilla,
• Shishi Jiang,
• Chuanchuan Sun,
• Michael R. Scudder,
• R. Dominic Ross and
• Joshua E. Goldberger

Beilstein J. Nanotechnol. 2017, 8, 1642–1648, doi:10.3762/bjnano.8.164

• -terminated graphane analogue of germanium has generated interest as a potential 2D electronic material. However, the incorporation and retention of extrinsic dopant atoms in the lattice, to tune the electronic properties, remains a significant challenge. Here, we show that the group-13 element Ga and the

• group-15 element As, can be successfully doped into a precursor CaGe2 phase, and remain intact in the lattice after the topotactic deintercalation, using HCl, to form GeH. After deintercalation, a maximum of 1.1% As and 2.3% Ga can be substituted into the germanium lattice. Electronic transport

• four days in ambient atmosphere. Overall, this work demonstrates that extrinsic doping with Ga is a viable pathway towards accessing stable electronic behavior in graphane analogues of germanium. Keywords: doping; electronic behavior; germanane; two-dimensional materials; Introduction Since the

The integration of graphene into microelectronic devices

• Guenther Ruhl,
• Sebastian Wittmann,
• Matthias Koenig and
• Daniel Neumaier

Beilstein J. Nanotechnol. 2017, 8, 1056–1064, doi:10.3762/bjnano.8.107

• /SiO2 substrate to graphene [31]. A newer procedure is the use of a suitable growth substrate that is compatible with device fabrication. Such a suitable substrate material is germanium [32][33] but only a limited choice of electronic devices can make use of Ge. Thus the transfer of graphene from this

• compressive strain of approximately −0.1% [49]. On epitaxial germanium(001) with a higher surface roughness there is a higher compressive strain in the range between −0.37% and −0.25% [33]. Thus, it is crucial to provide substrates as smooth as possible for graphene integration. 4 Encapsulation In order to

Copper atomic-scale transistors

• Fangqing Xie,
• Maryna N. Kavalenka,
• Moritz Röger,
• Daniel Albrecht,
• Hendrik Hölscher,
• Jürgen Leuthold and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2017, 8, 530–538, doi:10.3762/bjnano.8.57

• V) of the three most promising approaches, namely multigate transistors, tunnel field-effect transistors, and germanium nanodevices [59][60][61][62]. The dynamic power dissipation of the CMOS devices is proportional to the square of drain supply voltage (VDD) [58]. The copper atomic-scale

• an electrolyte of copper sulfate and sulfuric acid in bi-distilled water. The operational potentials of the copper atomic-scale transistor are compatible with the operation voltages (ca. 0.5 V) of multigate transistors, tunnel field-effect transistors, and germanium nanodevices [59][60][61][62

Obtaining and doping of InAs-QD/GaAs(001) nanostructures by ion beam sputtering

• Sergei N. Chebotarev,
• Alexander S. Pashchenko,
• Leonid S. Lunin,
• Elena N. Zhivotova,
• Georgy A. Erimeev and
• Marina L. Lunina

Beilstein J. Nanotechnol. 2017, 8, 12–20, doi:10.3762/bjnano.8.2

• being actively adapted for the growth of nanomaterials with quantum dots (QDs). Ion beam sputtering of germanium films was firstly carried out by Krikorian and Sneed [14]. Their work demonstrated a significant potential of the technique and became a starting point of its development. Ion beam

• homoepitaxy of silicon on substrates with (001) crystallographic orientation was in parts investigated by Lee and Xue [15]. High-vacuum ion beam heteroepitaxy of nanometer-thick germanium films on silicon substrates was carried out by Alexandrov and co-workers [16]. They were the first to observe the self

• -assembly growth of germanium quantum-dot nanostructures. Furthermore, ion beam sputtering was used for heteroepitaxy of Ge on GaAs substrates [17] and GaAs1−xPx on Si substrates [18]. In addition, the effect of ion beam bombardment of semiconductor surfaces is used at least for two applications. First, it

Surface-enhanced infrared absorption studies towards a new optical biosensor

• Lothar Leidner,
• Julia Stäb,
• Jennifer T. Adam and
• Günter Gauglitz

Beilstein J. Nanotechnol. 2016, 7, 1736–1742, doi:10.3762/bjnano.7.166

• nanoparticles. According to Yang and Griffiths [12], the ideal substrate for SEIRA is a thin film of isolated nanoparticles distributed over a suitable infrared transparent substrate. They report enhancement factors of approximately 100 for silver nanoparticles on a germanium substrate. An interesting approach

• nanoparticles and water structures. In this context, the work of Ishida and Griffiths [20] is interesting. The authors investigated water bands by a germanium internal reflection element (IRE) with deposited copper films. They observed not only enhanced absorption (SEIRA) of the bending mode of water molecules

Fingerprints of a size-dependent crossover in the dimensionality of electronic conduction in Au-seeded Ge nanowires

• Maria Koleśnik-Gray,
• Gillian Collins,
• Justin D. Holmes and
• Vojislav Krstić

Beilstein J. Nanotechnol. 2016, 7, 1574–1578, doi:10.3762/bjnano.7.151

• Ireland 10.3762/bjnano.7.151 Abstract We studied the electrical transport properties of Au-seeded germanium nanowires with radii ranging from 11 to 80 nm at ambient conditions. We found a non-trivial dependence of the electrical conductivity, mobility and carrier density on the radius size. In particular

• have quasi one-dimensional character as reflected by the extracted screening lengths. Keywords: electrical transport; germanium nanowires; quasi-1D confinement; screening length; VLS growth; Results and Discussion Synthetic germanium nanowires (Ge NWs) have been proposed as potential next-generation

Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

• Ionel Stavarache,
• Valentin Adrian Maraloiu,
• Petronela Prepelita and
• Gheorghe Iordache

Beilstein J. Nanotechnol. 2016, 7, 1492–1500, doi:10.3762/bjnano.7.142

• devices individually or with other materials, hence the possibility of fabricating various heterojunctions on Si, glass or flexible substrates for future development of Si-based integrated optoelectronics. Keywords: germanium nanoparticle; photocurrent; photodetectors; response time; transport mechanism

• % over the whole investigated frequency range (1–4 kHz), which is a good result compared with other new materials and test structures reported in literature (18% in the case of graphene monolayer/germanium heterojunctions or about 13% for MoS2/Si heterojunctions) [48][49]. This is an indication of the

Diameter-driven crossover in resistive behaviour of heavily doped self-seeded germanium nanowires

• Stephen Connaughton,
• Maria Koleśnik-Gray,
• Richard Hobbs,
• Olan Lotty,
• Justin D. Holmes and
• Vojislav Krstić

Beilstein J. Nanotechnol. 2016, 7, 1284–1288, doi:10.3762/bjnano.7.119

• (FAU), Staudtstraße 7, 91058 Erlangen, Germany Materials Chemistry & Analysis Group, Department of Chemistry, University College Cork, Cork, Republic of Ireland 10.3762/bjnano.7.119 Abstract The dependence of the resistivity with changing diameter of heavily-doped self-seeded germanium nanowires was

• spatial spreading of the free holes towards the nanowire centre upon diameter reduction. Keywords: diameter-dependence; germanium; nanowire; resistivity; self-seeded; Findings Semiconducting nanowires are in the focus of research due to their potential applications in electronics and optics [1][2][3][4

• ][5][6][7][8][9]. Germanium nanowires (Ge NWs) are of particular interest as they provide the prospect for quantum-related phenomena associated with one-dimensional (1D) confinement already at diameters of tens of nm [10], or determining their electronic properties by surface doping [11]. Among

Influence of calcium on ceramide-1-phosphate monolayers

• Joana S. L. Oliveira,
• Gerald Brezesinski,
• Alexandra Hill and
• Arne Gericke

Beilstein J. Nanotechnol. 2016, 7, 236–245, doi:10.3762/bjnano.7.22

• intensity of the diffracted beam as a function of the vertical scattering angle αf and the horizontal scattering angle 2θ. A Soller collimator (JJ X-Ray, Denmark) was located between the sample and the detector. At ID10 (ESRF, Grenoble) the synchrotron beam was monochromated by a germanium(111) crystal to a

Simulation of thermal stress and buckling instability in Si/Ge and Ge/Si core/shell nanowires

• Suvankar Das,
• Amitava Moitra,
• Mishreyee Bhattacharya and
• Amlan Dutta

Beilstein J. Nanotechnol. 2015, 6, 1970–1977, doi:10.3762/bjnano.6.201

• years, a drastic rise in the research activities on semiconductor core/shell nanowires (CSNWs) made of silicon and germanium has occurred. Such studies are often motivated by the excellent charge transport properties of the materials [1][2][3][4], for which they are now seen as prospective candidates

• . This behavior can be understood simply by observing the elastic modulus of the monoelemental NWs (represented as 10 nm core diameter). Silicon, being stiffer than germanium, shows a general tendency of an increasing Young’s modulus with a rise in its compositional contribution in the hetrerostructure

Atomic scale interface design and characterisation

• Carla Bittencourt,
• Chris Ewels and
• Arkady V. Krasheninnikov

Beilstein J. Nanotechnol. 2015, 6, 1708–1711, doi:10.3762/bjnano.6.174

• expanding range of applications for related nanomaterials such as boron nitride nanotubes [22] and silicon and germanium nanocrystals [23]. Recent developments in X-rays collimation optics triggered the interest in synchrotron radiation-based techniques for the study of nanostructures. In this context, X

Nanoporous Ge thin film production combining Ge sputtering and dopant implantation

• Jacques Perrin Toinin,
• Alain Portavoce,
• Khalid Hoummada,
• Michaël Texier,
• Maxime Bertoglio,
• Sandrine Bernardini,
• Marco Abbarchi and
• Lee Chow

Beilstein J. Nanotechnol. 2015, 6, 336–342, doi:10.3762/bjnano.6.32

• postannealing conditions. Keywords: germanium; ion implantation; porous material; Introduction Porous materials are of great interest for a large scope of industrial applications dealing with adsorption, catalysis, or molecular filtration and isolation. Furthermore, porous semiconductors can exhibit

• ) plan-view images of the as-implanted Se sample. The implantation induces the formation of three types of defects, randomly distributed on or in the germanium layer: (i) large clusters of Ge oxide with an average lateral size of ≈400 nm (composition analyzed by atom probe tomography, not reported here

Bright photoluminescence from ordered arrays of SiGe nanowires grown on Si(111)

• D. J. Lockwood,
• N. L. Rowell,
• A. Benkouider,
• A. Ronda,
• L. Favre and
• I. Berbezier

Beilstein J. Nanotechnol. 2014, 5, 2498–2504, doi:10.3762/bjnano.5.259

• occurring within the NWs. Keywords: bandgap; germanium; nanowires; near field; silicon; photoluminescence; Introduction Semiconductor nanowires (NWs) are thought of as promising building blocks for opto-electronic devices that exploit their novel electronic band structures generated by two-dimensional (2D

• Torr. The silicon flux was obtained from an electron beam evaporator and maintained constant during the deposition at 0.03 nm/s, while germanium was deposited from an effusion cell. The growth temperatures were varied between 380 and 600 °C and were controlled in real time using an infrared pyrometer

Si/Ge intermixing during Ge Stranski–Krastanov growth

• Alain Portavoce,
• Khalid Hoummada,
• Antoine Ronda,
• Dominique Mangelinck and
• Isabelle Berbezier

Beilstein J. Nanotechnol. 2014, 5, 2374–2382, doi:10.3762/bjnano.5.246

• concentration of about 15 atom %. The Ge distribution in the islands follows a cylindrical symmetry and Ge segregation is observed only in the {113} facets of the islands. The Ge composition of the wetting layer is not homogeneous, varying from 5 to 30 atom %. Keywords: atom probe tomography; germanium islands

Towards bottom-up nanopatterning of Prussian blue analogues

• Virgile Trannoy,
• Marco Faustini,
• David Grosso,
• Sandra Mazerat,
• François Brisset,
• Alexandre Dazzi and
• Anne Bleuzen

Beilstein J. Nanotechnol. 2014, 5, 1933–1943, doi:10.3762/bjnano.5.204

• ranging between 76 and 263 kHz. Images were processed by using WsXM software. Fourier transform-infrared (FTIR) spectra were collected in the attenuated total reflection (ATR) mode by using a Vertex 70 spectrometer with a germanium crystal. XPS spectra were collected on a SPECS (Phoibos MCD 150) X-ray

Silicon and germanium nanocrystals: properties and characterization

• Ivana Capan,
• Alexandra Carvalho and
• José Coutinho

Beilstein J. Nanotechnol. 2014, 5, 1787–1794, doi:10.3762/bjnano.5.189

• , Portugal 10.3762/bjnano.5.189 Abstract Group-IV nanocrystals have emerged as a promising group of materials that extends the realm of application of bulk diamond, silicon, germanium and related materials beyond their traditional boundaries. Over the last two decades of research, their potential for

• regard to growth, characterization and modeling of silicon and germanium nanocrystals and related materials. Keywords: characterization; germanium; modelling; nanocrystals; silicon; Review I Introduction Nanocrystals (NCs) have emerged as one of the preferred ways to control quantum phenomena at the

• stands as a highly versatile tool for a variety of purposes including synthesis, modification and characterization of materials. The synthesis of NCs made of silicon and germanium by means of ion beams has been extensively studied in the past years [23]. QDs size, shape and distribution can be controlled

Probing the electronic transport on the reconstructed Au/Ge(001) surface

• Franciszek Krok,
• Mark R. Kaspers,
• Alexander M. Bernhart,
• Marek Nikiel,
• Benedykt R. Jany,
• Paulina Indyka,
• Mateusz Wojtaszek,
• Rolf Möller and
• Christian A. Bobisch

Beilstein J. Nanotechnol. 2014, 5, 1463–1471, doi:10.3762/bjnano.5.159

• the domain boundaries. Experimental The germanium substrate is cut from a wafer of a n-type Ge(001) crystal with a resistivity of about 30 Ω·cm. The cleaning procedure of the substrate consists of a few cycles of 600 eV Ar+ ion sputtering at a sample temperature of 1040 K (as measured by a pyrometer

• by the corresponding ac component of the tunnelling current. Further experimental details can be found elsewhere [12][16]. The contact tips are placed such that the direction of the applied lateral current is mainly oriented orthogonal to the main direction of the germanium surface steps originating

• dashed line. It is clearly seen that the substrate surface region does not propagate with crystalline order to the Au cluster. A discontinuity region (about 2 nm wide), called in the image “cavity”, may either be a substrate depletion filled with carbon or disordered germanium. In both cases, this

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• temperature range, because silicon is a very stable material for temperatures in excess of 900 K. Silicon–germanium alloys, SiGe [38][39], and superlattices [40][41] showed a good Z factor value, of the order of 2 × 10−3 K−1 at 800 K. Furthermore, they can be used for power generation in devices exploiting

STM tip-assisted engineering of molecular nanostructures: PTCDA islands on Ge(001):H surfaces

• Amir A. Ahmad Zebari,
• Marek Kolmer and
• Jakub S. Prauzner-Bechcicki

Beilstein J. Nanotechnol. 2013, 4, 927–932, doi:10.3762/bjnano.4.104

• -tetracarboxylic dianhydride (PTCDA) molecular islands on a hydrogen passivated germanium surface, Ge(001):H, are presented. The application of bias voltage pulses in STM allows for the modification of the islands. We found that the presence of a scanning tip of the tunneling microscope facilitates and speeds the

• system [20]. Most of the islands have a height of 2.1 nm, what corresponds to 6 molecular layers. Insight into the electronic structure of the studied system is obtained by rt STS measurements (see Figure 1b). For a bare germanium surface a band gap of ≈0.2 eV is obtained, in fair agreement with

• PTCDA island on Ge(001):H is measured as 4.2 eV. The latter value corresponds well with results reported for thick films (>5 nm) [26][27][28][29]. The electronic properties of the PTCDA islands are very different from the underlying passivated germanium, and there are no other features in the bias

Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism

• Gregor Hlawacek,
• Vasilisa Veligura,
• Stefan Lorbek,
• Tijs F. Mocking,
• Antony George,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 507–512, doi:10.3762/bjnano.3.58

• larger deviation from the initial particle trajectory. We will discuss this in more depth in the next paragraph. For the present case in which a light adlayer (either carbon or cobalt) covers a heavier substrate (silicon or germanium), (1) does not play a significant role and (2) will be weak in general

Graphite, graphene on SiC, and graphene nanoribbons: Calculated images with a numerical FM-AFM

• Fabien Castanié,
• Laurent Nony,
• Sébastien Gauthier and
• Xavier Bouju

Beilstein J. Nanotechnol. 2012, 3, 301–311, doi:10.3762/bjnano.3.34

• , germanium, etc). Recent improvements of this potential [103] do not modify the results presented below. In the case of graphite, the van der Waals interaction between two layers is described by a standard Lennard-Jones potential: with ε = 0.011 eV and σ = 3.2963 Å. Results and Discussion Graphite surface