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Chey, Chan Oeurn
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Publications (10 of 14) Show all publications
Nour, E., Chey, C., Willander, M. & Nur, O. (2016). Low frequency accelerator sensor based on piezoelectric ZnO nanorods grown by low temperature scalable process. Physica Status Solidi (a) applications and materials science, 213(9), 2503-2508
Open this publication in new window or tab >>Low frequency accelerator sensor based on piezoelectric ZnO nanorods grown by low temperature scalable process
2016 (English)In: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 213, no 9, p. 2503-2508Article in journal (Refereed) Published
Abstract [en]

Piezoelectric vertically aligned zinc oxide (ZnO) nanorods (NRs) were grown by low temperature aqueous chemical approach and successfully used as a low frequency self-powered accelerator detector system. The nanogenerator (NG) device was tested under the influence of low frequency vibrations, different load masses, and finger prints pressure. The experimental results show relatively high sensitivity to frequencies as low as 5 Hz. This energy conversion device has produced a maximum output voltage of about 0.3 and 1.4 V under a frequency of 41 Hz and a mass of 1000 g, respectively. The fabricated NG can be used as an accelerator sensor with a good performance in the range from about 0.67 to 5.5 m s−2 with a sensitivity of 0.045 V s2 m−1. Furthermore, it has been demonstrated that the NG is able to harvest energy under finger-print scanning. The result from the finger-print pressure was consistent with the masses testing results. This energy-harvesting technology also provides a simple and cost-effective platform to capture low-frequency mechanical energy, i.e., body movements, and other applications like developing a sensitive finger print camera, etc.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2016
National Category
Nano Technology
Identifiers
urn:nbn:se:liu:diva-128901 (URN)10.1002/pssa.201600142 (DOI)000388318600035 ()
Note

Funding agencies: Advanced Functional Materials (AFM) at Linkoping University, Sweden; CeNano grant at Linkoping University, Sweden

Available from: 2016-06-07 Created: 2016-06-07 Last updated: 2024-01-08Bibliographically approved
Strelchuk, V. V., Nikolenko, A. S., Kolomys, O. F., Rarata, S. V., Avramenko, K. A., Lytvyn, P. M., . . . Willander, M. (2016). Optical and structural properties of Mn-doped ZnO nanorods grown by aqueous chemical growth for spintronic applications. Thin Solid Films, 601, 22-27
Open this publication in new window or tab >>Optical and structural properties of Mn-doped ZnO nanorods grown by aqueous chemical growth for spintronic applications
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2016 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 601, p. 22-27Article in journal (Refereed) Published
Abstract [en]

The effect of Mn-doping on the structural, morphological, optical and magnetic properties of the ZnO:Mn nanorods (NRs) synthesized by aqueous chemical process is reported. Grown ZnO:Mn NRs are shown to have hexagonal end facets and the diameters increasing with nominal Mn content. Optical absorption measurements show a decrease in optical band gap with increase of Mn concentration. Raman spectroscopy revealed significant modification of the lattice vibrational properties of the ZnO matrix upon Mn doping. The additional Mn-related vibrational mode, intensity of which increases with amount of Mn can be regarded as an evidence of Mn incorporation into the host lattice of the ZnO. At high Mn concentrations, coexistence of hexagonal Zn1-xMnxO phase along with the secondary phases of ZnMn2O4 cubic spinel is revealed. Magnetic properties of ZnO: Mn NRs are studied by combinatorial atomic force microscopy and magnetic force microscopy imaging, and obtained clear magnetic contrast at room temperature provides a strong evidence of ferromagnetic behavior. (C) 2015 Elsevier B.V. All rights reserved.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2016
Keywords
Zinc oxide; Nanorods; Aqueous chemical growth; Spintronics; Optical properties; Raman spectroscopy; Magnetic properties; Magnetic-force microscopy
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-126869 (URN)10.1016/j.tsf.2015.11.019 (DOI)000371348700006 ()
Available from: 2016-04-05 Created: 2016-04-05 Last updated: 2024-01-08
Satti Osman, E., Chey, C. O., Willander, M. & Nur, O. (2015). A flexible anisotropic self-powered piezoelectric direction sensor based on double sided ZnO nanowires configuration. Nanotechnology, 26(9), Article ID 095502.
Open this publication in new window or tab >>A flexible anisotropic self-powered piezoelectric direction sensor based on double sided ZnO nanowires configuration
2015 (English)In: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 26, no 9, article id 095502Article in journal (Refereed) Published
Abstract [en]

We have successfully synthesized highly dense and well aligned zinc oxide nanowires (NWs) on the two sides of a PEDOT: PSS substrate by a single step low temperature hydrothermal method. The grown sample was used to fabricate a double sided piezoelectric nanogenerator (NG). The maximum harvested output power density from the fabricated double sided NG configuration was about 4.44 mW cm(-2). The results obtained from the present double sided NG were approximately double the output from a single side. In addition to that, the voltage polarity of the harvested voltage from the two sides of the NG has been investigated. The results showed that upon bending, an anisotropic voltage polarity is generated on the two sides. Indicating that, this double sided NG can be used as a self-powered voltage polarity based direction sensor. The results of the present flexible double sided NG is very promising for harvesting energy from irregular mechanical energy sources in the surrounding environment. In addition, the fabricated configuration showed stability for sensing and can be used in surveillance and security applications.

Place, publisher, year, edition, pages
IOP Publishing: Hybrid Open Access, 2015
Keywords
hydrothermal growth; nanogenerator; energy harvesting; piezoelectric nanowires
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-115311 (URN)10.1088/0957-4484/26/9/095502 (DOI)000349494600012 ()25676711 (PubMedID)
Note

Funding Agencies|CeNano grant; Department of Science and Technology, Campus Norrkoping, Linkoping University, Norrkoping, SE-601 4 Norrkoping, Sweden

Available from: 2015-03-13 Created: 2015-03-13 Last updated: 2024-01-08Bibliographically approved
Alnoor, H., Chey, C. O., Pozina, G., Liu, X., Khranovskyy, V., Willander, M. & Nour, O. (2015). Effect of precursor solutions stirring on deep level defects concentration and spatial distribution in low temperature aqueous chemical synthesis of zinc oxide nanorods. AIP Advances, 5(8), Article ID 087180.
Open this publication in new window or tab >>Effect of precursor solutions stirring on deep level defects concentration and spatial distribution in low temperature aqueous chemical synthesis of zinc oxide nanorods
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2015 (English)In: AIP Advances, E-ISSN 2158-3226, Vol. 5, no 8, article id 087180Article in journal (Refereed) Published
Abstract [en]

Hexagonal c-axis oriented zinc oxide (ZnO) nanorods (NRs) with 120-300 nm diameters are synthesized via the low temperature aqueous chemical route at 80 degrees C on silver-coated glass substrates. The influence of varying the precursor solutions stirring durations on the concentration and spatial distributions of deep level defects in ZnO NRs is investigated. Room temperature micro-photoluminesnce (mu-PL) spectra were collected for all samples. Cathodoluminescence (CL) spectra of the as-synthesized NRs reveal a significant change in the intensity ratio of the near band edge emission (NBE) to the deep-level emission (DLE) peaks with increasing stirring durations. This is attributed to the variation in the concentration of the oxygen-deficiency with increasing stirring durations as suggested from the X-ray photoelectron spectroscopy analysis. Spatially resolved CL spectra taken along individual NRs revealed that stirring the precursor solutions for relatively short duration (1-3 h), which likely induced high super saturation under thermodynamic equilibrium during the synthesis process, is observed to favor the formation of point defects moving towards the tip of the NRs. In contrary, stirring for longer duration (5-15 h) will induce low super saturation favoring the formation of point defects located at the bottom of the NRs. These findings demonstrate that it is possible to control the concentration and spatial distribution of deep level defects in ZnO NRs by varying the stirring durations of the precursor solutions.

Place, publisher, year, edition, pages
AMER INST PHYSICS, 2015
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-122070 (URN)10.1063/1.4929981 (DOI)000360655900089 ()
Note

Funding Agencies|Avdanced Functional Materials (AFM) SFO project at Linkoping Univeristy, Sweden

Available from: 2015-12-18 Created: 2015-10-19 Last updated: 2024-01-08
Chey, C. O., Liu, X., Alnoor, H., Nur, O. & Willander, M. (2015). Fast piezoresistive sensor and UV photodetector based on Mn-doped ZnO nanorods. Physica Status Solidi. Rapid Research Letters, 9(1), 87-91
Open this publication in new window or tab >>Fast piezoresistive sensor and UV photodetector based on Mn-doped ZnO nanorods
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2015 (English)In: Physica Status Solidi. Rapid Research Letters, ISSN 1862-6254, E-ISSN 1862-6270, Vol. 9, no 1, p. 87-91Article in journal (Refereed) Published
Abstract [en]

A low cost hydrothermal synthesis method to synthesize Mn-doped ZnO nanorods (NRs) with controllable morphology and structure has been developed. Ammonia is used to tailor the ammonium hydroxide concentration, which provides a source of OH– for hydrolysis and precipitation during the growth instead of HMT. The morphological, chemical composition, structural, and electronic structure studies of the Mn-doped ZnO NRs show that the Mn-doped ZnO NRs have a hexagonal wurtzite ZnO structure along the c-axis and the Mn ions replace the Zn sites in the ZnO NRs matrix without any secondary phase of metallic manganese element and manganese oxides observed. The fabricated PEDOT:PSS/Zn0.85Mn0.15O Schottky diode based piezoresistive sensor and UV photodetector shows that the piezoresistive sensor has pressure sensitivity of 0.00617 kPa–1 for the pressure range from 1 kPa to 20 kP and 0.000180 kPa–1for the pressure range from 20 kPa to 320 kPa with relatively fast response time of 0.03 s and the UV photodetector has both relatively high responsivity and fast response time of 0.065 A/W and 2.75 s, respectively. The fabricated Schottky diode can be utilized as a very useful human-friendly interactive electronic device for mass/force sensor or UV photodetector in everyday living life. This developed device is very promising for small-size, low-cost and easy-to-customize application-specific requirements. (© 2014 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)

Place, publisher, year, edition, pages
John Wiley & Sons, 2015
Keywords
ZnO nanorods, Mn doping, hydrothermal method, piezoresistive sensors, ultraviolet photodetectors, optical properties
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-112912 (URN)10.1002/pssr.201409453 (DOI)000348763500015 ()
Available from: 2014-12-19 Created: 2014-12-19 Last updated: 2024-05-02Bibliographically approved
Echresh, A., Chey, C. O., Zargar Shoushtari, M., Nur, O. & Willander, M. (2015). Light emitting diode based on n-Zn0.94M0.06O nanorods/p-GaN (M= Cd and Ni) heterojunction under forward and reverse bias. Journal of Luminescence, 160, 305-310
Open this publication in new window or tab >>Light emitting diode based on n-Zn0.94M0.06O nanorods/p-GaN (M= Cd and Ni) heterojunction under forward and reverse bias
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2015 (English)In: Journal of Luminescence, ISSN 0022-2313, E-ISSN 1872-7883, Vol. 160, p. 305-310Article in journal (Refereed) Published
Abstract [en]

In this study, we report on the improvement in the optoelectronic properties of n-ZnO nanorods/p-GaN heterojunction. This was achieved by doping the ZnO with cadmium (Cd) and nickel (Ni). The ZnO and Zn0.94M0.06O nanorods grown hydrothermally on the p-GaN substrate were used to fabricate the light emitting diodes (LEDs). Structural measurement revealed that nanorods with wurtzite structure having a preferential orientation along the (002) c-axis. The UV-vis spectra show that the optical band gap of Zn0.94M0.06O nanorods is decreased in comparison to ZnO nanorods. Electrical measurements of the fabricated LEDs show an obvious rectifying behaviour with low threshold voltage. Electroluminescence (EL) characteristics of LEDs operated at forward and reverse bias were investigated. The EL spectra under forward bias show that doping ZnO nanorods with Cd and Ni led to an intensity enhancement of the broad peak in the visible region while the blue peak originating from the p-GaN substrate remains almost unaffected. The effect of doping was to reduce the valence band offsets and consequently more hole injection has occurred leading to the observed enhancement of the broad band in the visible region. Under reverse bias all heterojunction LEDs show the blue light emission peak originating from the p-GaN substrate.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
Nanorods; Heterojunctions; Doping; Optoelectronic properties; White light emitting diodes
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-116814 (URN)10.1016/j.jlumin.2014.12.037 (DOI)000350087100046 ()
Note

Funding Agencies|Linkoping University; Shahid Chamran University of Ahvaz

Available from: 2015-04-07 Created: 2015-04-07 Last updated: 2024-01-08
Echresh, A., Chey, C. O., Zargar Shoushtari, M., Khranovskyy, V., Nour, O. & Willander, M. (2015). UV photo-detector based on p-NiO thin film/n-ZnO nanorods heterojunction prepared by a simple process. Journal of Alloys and Compounds, 632, 165-171
Open this publication in new window or tab >>UV photo-detector based on p-NiO thin film/n-ZnO nanorods heterojunction prepared by a simple process
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2015 (English)In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 632, p. 165-171Article in journal (Refereed) Published
Abstract [en]

A UV photo-detector based on p-NiO thin film/n-ZnO nanorods heterojunction was fabricated using a simple two-step fabrication process. The aqueous chemical hydrothermal and thermal evaporation methods were combined to grow the ZnO nanorods and the NiO thin film, respectively. Structural investigation indicated that well aligned ZnO nanorods with hexagonal face having a preferential orientation along the c-axis (002) have been achieved and that the NiO thin film is covering all the ZnO nanorods. X-ray photoelectron spectroscopy (XPS) was used to investigate the band alignment of the heterojunction and the valence and the conduction band offsets were determined to be 1.50 eV and 1.83 eV, respectively. The current-voltage characteristics of the p-NiO thin film/ZnO nanorods heterojunction showed a clear rectifying behavior under both dark and UV illumination conditions. The response of the heterojunction diode was excellent regarding the photocurrent generation. Although other similar heterojunction diodes demonstrated lower threshold voltage, the rectification ratio and the sensitivity of the fabricated diode were superior in comparison to other similar heterojunctions reported recently, implying the vitality of the presented two-step process. (C) 2015 Elsevier B.V. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
ZnO nanorods; NiO thin film; UV photo-detector; Heterojunction
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:liu:diva-116939 (URN)10.1016/j.jallcom.2015.01.155 (DOI)000350388900026 ()
Note

Funding Agencies|Linkoping University; Shahid Chamran University of Ahvaz

Available from: 2015-04-13 Created: 2015-04-10 Last updated: 2024-01-08
Chey, C. O., Alnoor, H., Abbasi, M. A., Nur, O. & Willander, M. (2014). Fast synthesis, morphology transformation, structural and optical properties of ZnO nanorods grown by seed-free hydrothermal method. Physica Status Solidi (a) applications and materials science, 211(11), 2611-2615
Open this publication in new window or tab >>Fast synthesis, morphology transformation, structural and optical properties of ZnO nanorods grown by seed-free hydrothermal method
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2014 (English)In: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 211, no 11, p. 2611-2615Article in journal (Refereed) Published
Abstract [en]

A fast and low cost seed-free hydrothermal synthesis method to synthesize zinc oxide (ZnO) nanorods with controllable morphology, size and structure has been developed. Ammonia is used to react with water to tailor the ammonium hydroxide concentration, which provides a continuous source of OH− for hydrolysis and precipitation of the final products. Hence, allowing ZnO nanorods to growth on large areas of metal (Au and Ag coated glass), p-type Si and organic flexible (PEDOT: PSS) substrates. Increasing the growth time, the morphology transforms from pencil-like to hexagonal shape rod-like morphology. Within one hour the length of the ZnO nanorods has reached almost 1 µm. The optical characteristics has shown that the grown ZnO nanorods are dominated by two emission peaks, one is in the UV range centered at 381 nm and other one with relatively high intensity appears in the visible range and centered at 630 nm. While the growth duration was increased from 2 h to 6 h, the optical band gap was observed to increase from 2.8 eV to 3.24 eV, respectively. This fast and low cost method is suitable for LEDs, UV-photodetector, sensing, photocatalytic, multifunctional devices and other optoelectronic devices, which can be fabricated on any substrates, including flexible and foldable substrates.

Keywords
hydrothermal method, low temperature growth, seed-free growth ZnO, ZnO nanorods
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-112903 (URN)10.1002/pssa.201431311 (DOI)000344461800029 ()
Available from: 2014-12-19 Created: 2014-12-19 Last updated: 2024-01-08Bibliographically approved
Chey, C. O., Masood, A., Riazanova, A., Liu, X., Rao, K. V., Nur, O. & Willander, M. (2014). Synthesis of Fe-Doped ZnO Nanorods by Rapid Mixing Hydrothermal Method and Its Application for High Performance UV Photodetector. Journal of Nanomaterials, 2014(524530), 1-9
Open this publication in new window or tab >>Synthesis of Fe-Doped ZnO Nanorods by Rapid Mixing Hydrothermal Method and Its Application for High Performance UV Photodetector
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2014 (English)In: Journal of Nanomaterials, ISSN 1687-4110, E-ISSN 1687-4129, Vol. 2014, no 524530, p. 1-9Article in journal (Refereed) Published
Abstract [en]

We have successfully synthesized Fe-doped ZnO nanorods by a new and simple method in which the adopted approach is by using ammonia as a continuous source of OH for hydrolysis instead of hexamethylenetetramine (HMT). The energy dispersive X-ray (EDX) spectra revealed that the Fe peaks were presented in the grown Fe-doped ZnO nanorods samples and the X-ray photoelectron spectroscopy (XPS) results suggested that Fe3+ is incorporated into the ZnO lattice. Structural characterization indicated that the Fe-doped ZnO nanorods grow along the c-axis with a hexagonal wurtzite structure and have single crystalline nature without any secondary phases or clusters of FeO or Fe3O4 observed in the samples. The Fe-doped ZnO nanorods showed room temperature (300 K) ferromagnetic magnetization versus field (M-H) hysteresis and the magnetization increases from 2.5 μemu to 9.1 μemu for Zn0.99Fe0.01O and Zn0.95Fe0.05O, respectively. Moreover, the fabricated Au/Fe-doped ZnO Schottky diode based UV photodetector achieved 2.33 A/W of responsivity and 5 s of time response. Compared to other Au/ZnO nanorods Schottky devices, the presented responsivity is an improvement by a factor of 3.9.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2014
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-112914 (URN)10.1155/2014/524530 (DOI)000345016000001 ()
Available from: 2014-12-19 Created: 2014-12-19 Last updated: 2024-01-08
Chey, C. O. (2014). Synthesis of ZnO and transition metals doped ZnO nanostructures, their characterization and sensing applications. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Synthesis of ZnO and transition metals doped ZnO nanostructures, their characterization and sensing applications
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Nanotechnology is a technology of the design and the applications of nanoscale materials with their fundamentally new properties and functions. Nanosensor devices based on nanomaterials provide very fast response, low-cost, long-life time, easy to use for unskilled users, and provide high-efficiency.

1-D ZnO nanostructures materials have great potential applications in various sensing applications. ZnO is a wide band gap (3.37 eV at room temperature) semiconductor materials having large exciton binding energy (60 meV) and excellent chemical stability, electrical, optical, piezoelectric and pyroelectric properties. By doping the transition metals (TM) into ZnO matrix, the properties of ZnO nanostructures can be tuned and its room  temperature ferromagnetic behavior can be enhanced, which provide the TM-doped ZnO nanostructures as promising candidate for optoelectronic, spintronics and high performance sensors based devices. The synthesis of ZnO and TM-doped ZnO nanostructures via the low temperature hydrothermal method is considered a promising technique due to low cost, environmental friendly, simple solution process, diverse 1-D ZnO nanostructures can be achieved, and large scale production on any type of substrate, and their properties can be controlled by the growth parameters. However, to synthesize 1-D ZnO and TM-doped ZnO nanostructures with controlled shape, structure and uniform size distribution on large area substrates with desirable properties, low cost and simple processes are of high interest and it is a big challenge at present.

The main purpose of this dissertation aims to develop new techniques to synthesize 1-D ZnO and (Fe, Mn)-doped ZnO nanostructures via the hydrothermal method, to characterize and to enhance their functional properties for developing sensing devices such as biosensors for clinical diagnoses and environmental monitoring applications, piezoresistive sensors and UV photodetector.

The first part of the dissertation deals with the hydrothermal synthesis of ZnO nanostructures with controlled shape, structure and uniform size distribution under different conditions and their structural characterization. The possible parameters affecting the growth which can alter the morphology, uniformity and properties of the ZnO nanostructures were investigated. Well-aligned ZnO nanorods have been fabricated for high sensitive piezoresistive sensor. The development of creatinine biosensor for clinical diagnoses purpose and the development of glucose biosensor for indirect determination of mercury ions for an inexpensive and unskilled users for environmental monitoring applications with highly sensitive, selective, stable, reproducible, interference resistant, and fast response time have been fabricated based on ZnO nanorods.

The second part of the dissertation presents a new hydrothermal synthesis of (Fe, Mn)-doped-ZnO nanostructures under different preparation conditions, their properties characterization and the fabrication of piezoresistive sensors and UV photodetectors based devices were demonstrated. The solution preparation condition and growth parameters that influences on the morphology, structures and properties of the nanostructures were investigated. The fabrication of Mn-doped-ZnO NRs/PEDOT:PSS Schottky diodes used as high performance piezoresistive sensor and UV photodetector have been studied and Fe-doped ZnO NRs/FTO Schottky diode has also been fabricated for high performance of UV photodetector. Finally, a brief outlook into future challenges and relating new opportunities are presented in the last part of the dissertation.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2014. p. 74
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1629
Keywords
Synthesis ZnO nanostructures, TM-doped ZnO NRs, Hydrothermal method, Biosensors, Piezoresistive sensors, UV photodetectors, Diluted magnetic semiconductors
National Category
Physical Sciences Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-113237 (URN)10.3384/diss.diva-113237 (DOI)978-91-7519-206-2 (ISBN)
Public defence
2015-01-23, K3, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 10:00 (English)
Opponent
Supervisors
Available from: 2015-01-13 Created: 2015-01-13 Last updated: 2024-01-08Bibliographically approved
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