uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 86) Show all publications
Xu, X., Makaraviciute, A., Pettersson, J., Zhang, S.-L. & Zhang, Z. (2018). Considerations for the Cyclic Voltammetry of Gold in Sulfuric Acid Solutions. In: : . Paper presented at 69th Annual Meeting of the International Society of Electrochemistry in Bologna.
Open this publication in new window or tab >>Considerations for the Cyclic Voltammetry of Gold in Sulfuric Acid Solutions
Show others...
2018 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

A comprehensive understanding of the cyclic voltammetry (CV) for gold surfaces is essential for advanced applications. In the present study, a series of experiments were designed to investigate CV for gold under different experimental conditions when using a conventional configuration of a Ag/AgCl/sat. KCl reference electrode and a platinum wire counter electrode. The interferences introduced by the configuration were reflected in the three fingerprint regions of the voltammograms. It was found that the shape of the voltammograms was less reproducible at a lower sample volume when the cycle number was increased. This observation could be explained by different concentrations of Cl- leaking from the reference electrode and platinum dissolved from the counter electrode. The reproducibility of the gold oxidation and reduction (Ox/Re) region in the voltammograms was improved when gold dissolution and re-deposition caused by Cl- leakage was eliminated by using a bridge. In the hydrogen evolution and oxidation reactions (HER/HOR) region the catalytic performance of the gold electrode could be minimized by replacing the platinum counter electrode with a graphite rod. Alternatively, it could be enhanced by increasing the surface ratio of the co-deposited platinum to gold. In the electric double layer (EDL) region, peaks dependent on the concentrations of Cl- and SO42- were observed. To account for the occurrence of these peaks, a new mechanism based on the formation of neutral gold (I) complexes at very low Au+ concentrations, was proposed. 

National Category
Physical Chemistry Other Chemical Engineering
Identifiers
urn:nbn:se:uu:diva-363362 (URN)
Conference
69th Annual Meeting of the International Society of Electrochemistry in Bologna
Available from: 2018-10-17 Created: 2018-10-17 Last updated: 2018-10-18Bibliographically approved
Hu, Q., Chen, X., Norström, H., Zeng, S., Yifei, L., Fredrik, G., . . . Zhang, Z. (2018). Current gain and low-frequency noise of symmetriclateral bipolar junction transistors on SOI. In: : . Paper presented at 48th European Solid-State Device Research Conference.
Open this publication in new window or tab >>Current gain and low-frequency noise of symmetriclateral bipolar junction transistors on SOI
Show others...
2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a comprehensive study ofsymmetric lateral bipolar junction transistors (LBJTs) fabricatedon SOI substrate using a CMOS-compatible process; LBJTs findmany applications including being a local signal amplifier forsilicon-nanowire sensors. Our LBJTs are characterized by a peakgain (β) over 50 and low-frequency noise two orders ofmagnitude lower than what typically is of the SiO2/Si interfacefor a MOSFET. β is found to decrease at low base current due torecombination in the space charge region at the emitter-basejunction and at the surrounding SiO2/Si interfaces. This decreasecan be mitigated by properly biasing the substrate.

Keywords
symmetric lateral bipolar junction transitor; current amplification; low frequency noise; silicon nanowire field-effect transitor
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-364155 (URN)
Conference
48th European Solid-State Device Research Conference
Note

Qitao Hu and Xi Chen contribute equally to the work.

Available from: 2018-10-24 Created: 2018-10-24 Last updated: 2018-10-24
Jablonka, L., Riekehr, L., Zhang, Z., Zhang, S.-L. & Kubart, T. (2018). Highly conductive ultrathin Co films by high-power impulse magnetron sputtering. Applied Physics Letters, 112(4), Article ID 043103.
Open this publication in new window or tab >>Highly conductive ultrathin Co films by high-power impulse magnetron sputtering
Show others...
2018 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 112, no 4, article id 043103Article in journal (Refereed) Published
Abstract [en]

Ultrathin Co films deposited on SiO2 with conductivities exceeding that of Cu are demonstrated. Ionized deposition implemented by high-power impulse magnetron sputtering (HiPIMS) is shown to result in smooth films with large grains and low resistivities, namely, 14 mu Omega cm at a thickness of 40 nm, which is close to the bulk value of Co. Even at a thickness of only 6 nm, a resistivity of 35 mu Omega cm is obtained. The improved film quality is attributed to a higher nucleation density in the Co-ion dominated plasma in HiPIMS. In particular, the pulsed nature of the Co flux as well as shallow ion implantation of Co into SiO2 can increase the nucleation density. Adatom diffusion is further enhanced in the ionized process, resulting in a dense microstructure. These results are in contrast to Co deposited by conventional direct current magnetron sputtering where the conductivity is reduced due to smaller grains, voids, rougher interfaces, and Ar incorporation. The resistivity of the HiPIMS films is shown to be in accordance with models by Mayadas-Shatzkes and Sondheimer which consider grain-boundary and surface-scattering.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2018
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-340315 (URN)10.1063/1.5011109 (DOI)000423724300039 ()
Funder
Swedish Foundation for Strategic Research , SE13-0033Swedish Foundation for Strategic Research , RIF14-0053Swedish Research Council, C0514401
Available from: 2018-01-29 Created: 2018-01-29 Last updated: 2018-04-04Bibliographically approved
Jablonka, L., Kubart, T., Gustavsson, F., Descoins, M., Mangelinck, D., Zhang, S.-L. & Zhang, Z. (2018). Improving the morphological stability of nickel germanide by tantalum and tungsten additions. Applied Physics Letters, 112(10)
Open this publication in new window or tab >>Improving the morphological stability of nickel germanide by tantalum and tungsten additions
Show others...
2018 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 112, no 10Article in journal (Refereed) Published
Abstract [en]

To enhance the morphological stability of NiGe, a material of interest as a source drain-contact in Ge-based field effect transistors, Ta or W, is added as either an interlayer or a capping layer. The efficacy of this Ta or W addition is evaluated with pure NiGe as a reference. While interlayers increase the NiGe formation temperature, capping layers do not retard the NiGe formation. Regardless of the initial position of Ta or W, the morphological stability of NiGe against agglomeration can be improved by up to 100 °C. The improved thermal stability can be ascribed to an inhibited surface diffusion, owing to Ta or W being located on top of NiGe after annealing, as confirmed by means of transmission electron microscopy, Rutherford backscattering spectrometry, and atom probe tomography. The latter also shows a 0.3 €‰at. % solubility of Ta in NiGe at 450 °C, while no such incorporation of W is detectable.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-344676 (URN)10.1063/1.5019440 (DOI)
Funder
Swedish Foundation for Strategic Research , SE13- 0033Swedish Foundation for Strategic Research , RIF14- 0053Swedish Research Council, C0514401
Available from: 2018-03-07 Created: 2018-03-07 Last updated: 2018-05-18Bibliographically approved
Zhang, D., Solomon, P., Zhang, S.-L. & Zhang, Z. (2018). Low-frequency noise originating from the dynamic hydrogen ion reactivity at the solid/liquid interface of ion sensors. In: : . Paper presented at China Semiconductor Technology International Conference (CSTIC).
Open this publication in new window or tab >>Low-frequency noise originating from the dynamic hydrogen ion reactivity at the solid/liquid interface of ion sensors
2018 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

Low-frequency noise (LFN) is of significant implications in ion sensing. As a primary component of LFN for ion sensing in electrolytes, the solid/liquid interfacial noise remains poorly explored especially regarding its relation to the surface binding/de-binding dynamic properties. In this talk, the solid/liquid interfacial noise will first be characterized by direct electrical measurements. It will then be correlated to the dynamic properties of surface protonation (i.e., hydrogen binding) and deprotonation (i.e., hydrogen de-binding) processes using an impedance spectroscopy. Finally we will provide insights into how detailed surface properties may affect the noise performance of an ion sensor operating in electrolytes.

National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-347580 (URN)
Conference
China Semiconductor Technology International Conference (CSTIC)
Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-09
Chen, X., Hu, Q., Chen, S., Netzer, N. L., Wang, Z., Zhang, S.-L. & Zhang, Z. (2018). Multiplexed analysis of molecular and elemental ions using nanowire transistor sensors. Sensors and actuators. B, Chemical, 270, 89-96
Open this publication in new window or tab >>Multiplexed analysis of molecular and elemental ions using nanowire transistor sensors
Show others...
2018 (English)In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 270, p. 89-96Article in journal (Refereed) Published
Abstract [en]

An integrated sensor chip with silicon nanowire ion-sensitive field-effect transistors for simultaneous and selective detection of both molecular and elemental ions in a single sample solution is demonstrated. The sensing selectivity is realized by functionalizing the sensor surface with tailor-made mixed-matrix membranes (MMM) incorporated with specific ionophores for the target ions. A biomimetic container molecule, named metal-organic supercontainer (MOSC), is selected as the ionophore for detection of methylene blue (MB+), a molecular ion, while a commercially available Na-ionophore is used for Na+, an elemental ion. The sensors show a near-Nernstian response with 56.4 ± 1.8 mV/dec down to a concentration limit of ∌1 ΌM for MB+ and 57.9 ± 0.7 mV/dec down to ∌60 ΌM for Na+, both with excellent reproducibility. Extensive control experiments on the MB+ sensor lead to identification of the critical role of the MOSC molecules in achieving a stable and reproducible potentiometric response. Moreover, the MB+-specific sensor shows remarkable selectivity against common interfering elemental ions in physiological samples, e.g., H+, Na+, and K+. Although the Na+-specific sensor is currently characterized by insufficient immunity to the interference by MB+, the root cause is identified and remedies generally applicable for hydrophobic molecular ions are discussed. River water experiments are also conducted to prove the efficacy of our sensors.

Keywords
Elemental ion, ISFET, Metal-organic supercontainer, Molecular ion, Multiplex detection, Silicon nanowire FET
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-351716 (URN)10.1016/j.snb.2018.05.018 (DOI)000434011500011 ()
Funder
Swedish Foundation for Strategic Research , SSF ICA 12-0047;FFL15-0174Swedish Research Council, VR 2014-5588Göran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology, GG 1459BCarl Tryggers foundation , CTS14-527
Note

Xi Chen and Qitao Hu contributed equally to this work

Available from: 2018-05-29 Created: 2018-05-29 Last updated: 2018-08-31Bibliographically approved
Wu, J., Mahajan, A., Riekehr, L., Zhang, H., Yang, B., Meng, N., . . . Yan, H. (2018). Perovskite Sr-x(Bi1-xNa0.97-xLi0.03)(0.5)TiO3 ceramics with polar nano regions for high power energy storage. Nano Energy, 50, 723-732
Open this publication in new window or tab >>Perovskite Sr-x(Bi1-xNa0.97-xLi0.03)(0.5)TiO3 ceramics with polar nano regions for high power energy storage
Show others...
2018 (English)In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 50, p. 723-732Article in journal (Refereed) Published
Abstract [en]

Dielectric capacitors are very attractive for high power energy storage. However, the low energy density of these capacitors, which is mainly limited by the dielectric materials, is still the bottleneck for their applications. In this work, lead-free single-phase perovskite Srx(Bi1-xNa0.97-xLi0.03)(0.5)TiO3 (x = 0.30 and 0.38) bulk ceramics, prepared using solid-state reaction method, were carefully studied for the dielectric capacitor application. Polar nano regions (PNRs) were created in this material using co-substitution at A-site to enable relaxor behaviour with low remnant polarization (P-r) and high maximum polarization (P-max). Moreover, P-max was further increased due to the electric field induced reversible phase transitions in nano regions. Comprehensive structural and electrical studies were performed to confirm the PNRs and reversible phase transitions. And finally a high energy density (1.70 J/cm(3)) with an excellent efficiency (87.2%) was achieved using the contribution of field-induced rotations of PNRs and PNR-related reversible transitions in this material, making it among the best performing lead-free dielectric ceramic bulk material for high energy storage.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2018
Keywords
Relaxor Ferroelectric, Dielectric, Polar Nano Regions, Energy Storage
National Category
Condensed Matter Physics Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-361041 (URN)10.1016/j.nanoen.2018.06.016 (DOI)000438076200084 ()
Funder
Swedish Foundation for Strategic Research , FFL15-0174
Available from: 2018-09-21 Created: 2018-09-21 Last updated: 2018-10-09Bibliographically approved
Hinnemo, M., Makaraviciute, A., Ahlberg, P., Olsson, J., Zhang, Z., Zhang, S.-L. & Zhang, Z.-B. (2018). Protein sensing beyond the Debye Length Using Graphene Field-effect Transistors. IEEE Sensors Journal, 18(16), 6497-6503
Open this publication in new window or tab >>Protein sensing beyond the Debye Length Using Graphene Field-effect Transistors
Show others...
2018 (English)In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 18, no 16, p. 6497-6503Article in journal (Refereed) Published
Abstract [en]

Sensing biomolecules in electrolytes of high ionic strength has been a difficult challenge for field-effect transistor-based sensors. Here, we present a graphene-based transistor sensor that is capable of detection of antibodies against protein p53 in electrolytes of physiological ionic strength without dilution. As these molecules are much larger than the Debye screening length at physiological ionic strengths, this paper proves the concept of detection beyond the Debye length. The measured signal associated with the expected specific binding of the antibodies to p53 is concluded to result from resistance changes at the graphene-electrolyte interface, since a sensor responding to resistance changes rather than charge variations is not limited by Debye screening. The conclusion with changes in interface resistance as the underlying phenomena that lead to the observed signal is validated by impedance spectroscopy, which indeed shows an increase of the total impedance in proportion to the amounts of bound antibodies. This finding opens up a new route for electrical detection of large-size and even neutral biomolecules for biomedical detection applications with miniaturized sensors.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Engineering Science with specialization in Electronics
Identifiers
urn:nbn:se:uu:diva-317088 (URN)10.1109/JSEN.2018.2849006 (DOI)000439966100003 ()
Funder
Knut and Alice Wallenberg Foundation, 2011.0113 2011.0082Swedish Foundation for Strategic Research , SE13-0061Swedish Research Council, 2014-5591 2014-5588
Available from: 2017-03-10 Created: 2017-03-10 Last updated: 2018-11-12Bibliographically approved
Zhang, D., Solomon, P., Zhang, S.-L. & Zhang, Z. (2017). An impedance model for the low-frequency noise originating from the dynamic hydrogen ion reactivity at the solid/liquid interface. Sensors and actuators. B, Chemical, 254, 363-369
Open this publication in new window or tab >>An impedance model for the low-frequency noise originating from the dynamic hydrogen ion reactivity at the solid/liquid interface
2017 (English)In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 254, p. 363-369Article in journal (Refereed) Published
Abstract [en]

Understanding the dynamics of hydrogen ion reactivity at the solid/liquid interface is of paramount importance for applications involving ion sensing in electrolytes. However, the correlation of this interfacial process to noise generation is poorly characterized. Here, the relationship is unveiled by characterizing the interfacial process with impedance spectroscopy assisted by a dedicated electrochemical impedance model. The model incorporates both thermodynamic and kinetic properties of the amphoteric hydrogen ion site-binding reactions with the surface OH groups. It further takes into consideration the distributed nature of the characteristic energy of the binding sites. The simulated impedance matches the experimental data better with an energy distribution of the kinetic parameters than with that of the thermodynamic ones. Since the potentiometric low-frequency noise (LFN) originating from the solid/liquid interface correlates excellently with the real part of its electrochemical impedance spectrum, this work establishes a method for evaluating sensing surface quality aimed at mitigating LFN.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-326714 (URN)10.1016/j.snb.2017.07.054 (DOI)000413308000045 ()
Funder
Swedish Research Council, VR 2014-5588Göran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology, GG 1459BCarl Tryggers foundation , CTS14-527Stiftelsen Olle Engkvist Byggmästare, 2016/39
Available from: 2017-07-26 Created: 2017-07-26 Last updated: 2018-04-11Bibliographically approved
Netzer, N. L., Must, I., Qiao, Y., Zhang, S.-L., Wang, Z. & Zhang, Z. (2017). Biomimetic supercontainers for size-selective electrochemical sensing of molecular ions. Scientific Reports, 7, Article ID 45786.
Open this publication in new window or tab >>Biomimetic supercontainers for size-selective electrochemical sensing of molecular ions
Show others...
2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 45786Article in journal (Refereed) Published
Abstract [en]

New ionophores are essential for advancing the art of selective ion sensing. Metal-organic supercontainers (MOSCs), a new family of biomimetic coordination capsules designed using sulfonylcalix[4] arenes as container precursors, are known for their tunable molecular recognition capabilities towards an array of guests. Herein, we demonstrate the use of MOSCs as a new class of size-selective ionophores dedicated to electrochemical sensing of molecular ions. Specifically, a MOSC molecule with its cavities matching the size of methylene blue (MB+), a versatile organic molecule used for bio-recognition, was incorporated into a polymeric mixed-matrix membrane and used as an ion-selective electrode. This MOSC-incorporated electrode showed a near-Nernstian potentiometric response to MB+ in the nano-to micro-molar range. The exceptional size-selectivity was also evident through contrast studies. To demonstrate the practical utility of our approach, a simulated wastewater experiment was conducted using water from the Fyris River (Sweden). It not only showed a near-Nernstian response to MB+ but also revealed a possible method for potentiometric titration of the redox indicator. Our study thus represents a new paradigm for the rational design of ionophores that can rapidly and precisely monitor molecular ions relevant to environmental, biomedical, and other related areas.

Place, publisher, year, edition, pages
NATURE PUBLISHING GROUP, 2017
National Category
Chemical Sciences Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-321839 (URN)10.1038/srep45786 (DOI)000398960200001 ()28393841 (PubMedID)
Funder
Swedish Foundation for Strategic Research , SSF ICA 12-0047Swedish Research Council, VR 2014-5588Göran Gustafsson Foundation for Research in Natural Sciences and Medicine, GG 1459BCarl Tryggers foundation , CTS14-527
Available from: 2017-05-15 Created: 2017-05-15 Last updated: 2017-05-16Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4317-9701

Search in DiVA

Show all publications