Amorphous sub-nanometre Tb-doped SiO x N y /SiO 2 superlattices for optoelectronics

Amorphous sub-nanometre Tb-doped SiO x N y /SiO 2 superlattices were fabricated by means of alternating deposition of 0.7 nm thick Tb-doped SiO x N y layers and of 0.9 nm thick SiO 2 barrier layers in an electron-cyclotron-resonance plasma enhanced chemical vapour deposition system with in situ Tb-doping capability. High resolution transmission electron microscopy images showed a well-preserved superlattice morphology after annealing at a high temperature of 1000 °C. In addition, transparent indium tin oxide (ITO) electrodes were deposited by electron beam evaporation using a shadow mask approach to allow for the optoelectronic characterization of superlattices. Tb 3+ luminescent spectral features were obtained using three different excitation sources: UV laser excitation (photoluminescence (PL)), under a bias voltage (electroluminescence (EL)) and under a highly energetic electr...

Joan Manel Ramírez, Jacek Wojcik, Yonder Berencén, Alícia Ruiz-Caridad, Sònia Estradé, Francesca Peiró, Peter Mascher and Blas Garrido

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Axial p–n-junctions in nanowires

The charge distribution and potential profile of p–n-junctions in thin semiconductor nanowires (NWs) were analyzed. The characteristics of screening in one-dimensional systems result in a specific profile with large electric field at the boundary between the n- and p- regions, and long tails with a logarithmic drop in the potential and charge density. As a result of these tails, the junction properties depend sensitively on the geometry of external contacts and its capacity has an anomalously large value and frequency dispersion. In the presence of an external voltage, electrons and holes in the NWs can not be described by constant quasi-Fermi levels, due to small values of the average electric field, mobility, and lifetime of carriers. Thus, instead of the classical Sah–Noice–Shockley theory, the junction current–voltage characteristic was described by an alternative theory suitable for fast generation–recombination and slow diffusion–drift processes. For the non-uniform electri...

C Fernandes, A Shik, K Byrne, D Lynall, M Blumin, I Saveliev and H E Ruda

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Large-scale synthesis of high quality InP quantum dots in a continuous flow-reactor under supercritical conditions

The synthesis of indium phosphide quantum dots (QDs) in toluene under supercritical conditions was carried out in a macroscopic continuous flow reaction system. The results of first experiments are reported in comparison with analogous reactions in octadecene. The reaction system is described and details are provided about special procedures that are enabled by the continuous flow system for the screening of reaction conditions. The produced QDs show very narrow emission peaks with full width at half maximum down to 45 nm and reasonable photoluminescence quantum yields. The subsequent purification process is facilitated by the ease of removal of toluene, and the productivity of the system is increased by high temperature and high pressure conditions.

Christian Ippen, Benjamin Schneider, Christopher Pries, Stefan Kröpke, Tonino Greco and Andreas Holländer

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Solvothermal synthesis of stable nanoporous polymeric bases-crystalline TiO 2 nanocomposites: visible light active and efficient photocatalysts for water treatment

Visible light active and stable nanoporous polymeric base–crystalline TiO 2 nanocomposites were solvothermally synthesized from in situ copolymerization of divinylbenzene (DVB) with 1-vinylimidazolate (VI) or 4-vinylpyridine (Py) in the presence of tetrabutyl titanate without the use of any other additives (PDVB-VI-TiO 2 - x , PDVB-Py-TiO 2 - x , where x stands for the molar ratio of TiO 2 to VI or Py), which showed excellent activity with respect to catalyzing the degradation of organic pollutants of p -nitrophenol (PNP) and rhodamine-B (RhB). TEM and SEM images show that PDVB-VI-TiO 2 - x and PDVB-Py-TiO 2 - x have abundant nanopores, and TiO 2 nanocrystals with a high degree of crystallinity were homogeneously embedded in the PDVB-VI-TiO 2 - x and PDVB-Py-TiO 2 - x , forming a stable ‘brick-and-mortar’ nanostructure. PDVB-VI and PDVB-Py suppo...

Fujian Liu, Weiping Kong, Liang Wang, Iman Noshadi, Zhonghua Zhang and Chenze Qi

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Amorphous sub-nanometre Tb-doped SiO x N y /SiO 2 superlattices for optoelectronics

Amorphous sub-nanometre Tb-doped SiO x N y /SiO 2 superlattices were fabricated by means of alternating deposition of 0.7 nm thick Tb-doped SiO x N y layers and of 0.9 nm thick SiO 2 barrier layers in an electron-cyclotron-resonance plasma enhanced chemical vapour deposition system with in situ Tb-doping capability. High resolution transmission electron microscopy images showed a well-preserved superlattice morphology after annealing at a high temperature of 1000 °C. In addition, transparent indium tin oxide (ITO) electrodes were deposited by electron beam evaporation using a shadow mask approach to allow for the optoelectronic characterization of superlattices. Tb 3+ luminescent spectral features were obtained using three different excitation sources: UV laser excitation (photoluminescence (PL)), under a bias voltage (electroluminescence (EL)) and under a highly energetic electr...

Joan Manel Ramírez, Jacek Wojcik, Yonder Berencén, Alícia Ruiz-Caridad, Sònia Estradé, Francesca Peiró, Peter Mascher and Blas Garrido

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Compatibility of the selective area growth of GaN nanowires on AlN-buffered Si substrates with the operation of light emitting diodes

AlN layers with thicknesses between 2 and 14 nm were grown on Si(111) substrates by molecular beam epitaxy. The effect of the AlN layer thickness on the morphology and nucleation time of spontaneously formed GaN nanowires (NWs) was investigated by scanning electron microscopy and line-of-sight quadrupole mass spectrometry, respectively. We observed that the alignment of the NWs grown on these layers improves with increasing layer thickness while their nucleation time decreases. Our results show that 4 nm is the smallest thickness of the AlN layer that allows the growth of well-aligned NWs with short nucleation time. Such an AlN buffer layer was successfully employed, together with a patterned SiO x mask, for the selective-area growth (SAG) of vertical GaN NWs. In addition, we fabricated light-emitting diodes (LEDs) from NW ensembles that were grown by means of self-organization phenomena on bare and on AlN-buffered Si substrates. A careful characterization of the...

M Musolino, A Tahraoui, S Fernández-Garrido, O Brandt, A Trampert, L Geelhaar and H Riechert

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Transfer of self-aligned spacer patterns for single-digit nanofabrication

We report the transfer of sub-10 nm half-pitch grating patterns created through a combination of block copolymer directed self-assembly and sidewall spacer-based self-aligned double patterning into Si substrates. Low substrate bias reactive ion etching of TiO x conformally deposited onto carbon mandrels using atomic layer deposition renders distinct, pitch-halved spacers with minimal etch byproduct redeposition. Independent spacer and mandrel width control and the use of an underlying CrN x hard mask deposited by reactive sputtering facilitates etching of Si lines with low roughness and fine placement control. The insights into pattern transfer presented here are directly applicable to the fabrication of rectangular bit pattern nanoimprint templates at densities above 1.5 Td in −2 .

Gregory S Doerk, He Gao, Lei Wan, Jeff Lille, K C Patel, Yves-Andre Chapuis, Ricardo Ruiz and Thomas R Albrecht

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Fabrication of Micropatterned Polymeric Nanowire Arrays for High-Resolution Reagent Localization and Topographical Cellular Control

Nano Letters

DOI: 10.1021/nl503872p

Cade B. Fox, Jean Kim, Erica B. Schlesinger, Hariharasudhan D. Chirra and Tejal A. Desai

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Auger-Mediated Electron Relaxation Is Robust to Deep Hole Traps: Time-Domain Ab Initio Study of CdSe Quantum Dots

Nano Letters

DOI: 10.1021/nl504982k

Dhara J. Trivedi, Linjun Wang and Oleg V. Prezhdo

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Slurryless Li2S/Reduced Graphene Oxide Cathode Paper for High-Performance Lithium Sulfur Battery

Nano Letters

DOI: 10.1021/acs.nanolett.5b00112

Chao Wang, Xusheng Wang, Yuan Yang, Akihiro Kushima, Jitao Chen, Yunhui Huang and Ju Li

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Structural, Vibrational, and Magnetic Properties of FeCoOn0/+ (n = 1–6) Bimetallic Oxide Clusters

The Journal of Physical Chemistry C

DOI: 10.1021/jp5121349

M. B. Torres, A. Aguado, F. Aguilera-Granja, A. Vega and L. C. Balbás

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Characterization of Planar Lead Halide Perovskite Solar Cells by Impedance Spectroscopy, Open-Circuit Photovoltage Decay, and Intensity-Modulated Photovoltage/Photocurrent Spectroscopy

The Journal of Physical Chemistry C

DOI: 10.1021/jp510837q

Adam Pockett, Giles E. Eperon, Timo Peltola, Henry J. Snaith, Alison Walker, Laurence M. Peter and Petra J. Cameron

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Highly Scalable, Uniform, and Sensitive Biosensors Based on Top-Down Indium Oxide Nanoribbons and Electronic Enzyme-Linked Immunosorbent Assay

Nano Letters

DOI: 10.1021/nl5047889

Noppadol Aroonyadet, Xiaoli Wang, Yan Song, Haitian Chen, Richard J. Cote, Mark E. Thompson, Ram H. Datar and Chongwu Zhou

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Control of Emergent Properties at a Correlated Oxide Interface with Graphene

Nano Letters

DOI: 10.1021/nl504170d

You Zhou, Jungwon Park, Jian Shi, Manish Chhowalla, Hyesung Park, David A. Weitz and Shriram Ramanathan

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Oxygen Atom Exchange between Gaseous CO2 and TiO2 Nanoclusters

The Journal of Physical Chemistry C

DOI: 10.1021/jp512059b

Svatopluk Civiš, Martin Ferus, Markéta Zukalová, Arnošt Zukal, Ladislav Kavan, Kenneth D. Jordan and Dan C. Sorescu

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Enhanced Organic Solar Cell Stability by Polymer (PCPDTBT) Side Chain Functionalization

Chemistry of Materials

DOI: 10.1021/cm504391k

Jurgen Kesters, Pieter Verstappen, Jorne Raymakers, Wouter Vanormelingen, Jeroen Drijkoningen, Jan D’Haen, Jean Manca, Laurence Lutsen, Dirk Vanderzande and Wouter Maes

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Intercalation of Benzoxaborolate Anions in Layered Double Hydroxides: Toward Hybrid Formulations for Benzoxaborole Drugs

Chemistry of Materials

DOI: 10.1021/cm504181w

Saad Sene, Sylvie Bégu, Christel Gervais, Guillaume Renaudin, Adel Mesbah, Mark E. Smith, P. Hubert Mutin, Arie van der Lee, Jean-Marie Nedelec, Christian Bonhomme and Danielle Laurencin

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Electronic and Chemical Properties of Germanene: The Crucial Role of Buckling

The Journal of Physical Chemistry C

DOI: 10.1021/jp511488m

A. Nijamudheen, Rameswar Bhattacharjee, Snehashis Choudhury and Ayan Datta

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Anode Material Associated with Polymeric Networking of Triflate Ions Formed on Mg

The Journal of Physical Chemistry C

DOI: 10.1021/jp5114015

Tohru Shiga, Yuichi Kato, Masae Inoue, Naoko Takahashi and Yoko Hase

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Enhanced Electrical Transparency by Ultrathin LaAlO3 Insertion at Oxide Metal/Semiconductor Heterointerfaces

Nano Letters

DOI: 10.1021/nl504169m

Takeaki Yajima, Makoto Minohara, Christopher Bell, Hiroshi Kumigashira, Masaharu Oshima, Harold Y. Hwang and Yasuyuki Hikita

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