| 1. |
- Coll, M., et al.
(författare)
-
Towards Oxide Electronics: a Roadmap
- 2019
-
Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 482, s. 1-93
-
Tidskriftsartikel (refereegranskat)abstract
- At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore’s law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and heterostructures, in sectors as data storage and computing, optics and plasmonics, magnonics, energy conversion and harvesting, and power electronics.
|
|
| 2. |
- Aijaz, Asim, et al.
(författare)
-
Low-temperature synthesis of thermochromic vanadium dioxide thin films by reactive high power impulse magnetron sputtering
- 2016
-
Ingår i: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 149, s. 137-144
-
Tidskriftsartikel (refereegranskat)abstract
- Thermochromic (TC) vanadium dioxide thin films provide means for controlling solar energy throughput and can be used for energy-saving applications such as smart windows. One of the factors limiting the deployment of VO2 films in TC devices is the growth temperature tau(s). At present, temperatures in excess of 450 degrees C are required, which clearly can be an impediment especially for temperature-sensitive substrates. Here we address the issue of high tau(s) by synthesizing VO2 thin films from highly ionized fluxes of depositing species generated in high power impulse magnetron sputtering (HiPIMS) discharges. The use of ions facilitates low-temperature film growth because the energy of the depositing species can be readily manipulated by substrate bias. For comparison, films were also synthesized by pulsed direct current magnetron sputtering. Structural and optical characterization of VO2 thin films on ITO-coated glass substrates confirms previous results that HiPIMS allows tau(s) to be reduced from 500 to 300 degrees C. Importantly, we demonstrated that HiPIMS permits the composition and TC response of the films to be tuned by altering the energy of the deposition flux via substrate bias. An optimum ion energy of 100 eV was identified, which points at a potential for further reduction of tau(s) thereby opening new possibilities for industrially-relevant applications of VO2-based TC thin films. Weak TC activity was observed even at tau(s) approximate to 200 degrees C in HiPIMS-produced films.
|
|
| 3. |
|
|
| 4. |
- Arvizu, Miguel A, et al.
(författare)
-
Rejuvenation of degraded electrochromic MoO3 thin films made by DC magnetron sputtering : Preliminary results
- 2016
-
Ingår i: Journal of Physics: Conference Series. - : Institute of Physics Publishing (IOPP).
-
Konferensbidrag (refereegranskat)abstract
- Molybdenum oxide thin films were deposited by reactive DC magnetron sputtering and were subjected to voltammetric cycling in an electrolyte comprised of lithium perchlorate in propylene carbonate. The films were heavily degraded during 20 voltammetric cycles in an extended voltage range. The films were subsequently rejuvenated by use of potentiostatic treatments under different voltages during 20 hours. Optical changes were recorded during the electrochemical degradation and ensuing rejuvenation.
|
|
| 5. |
- Atak, Gamze, et al.
(författare)
-
Electrochromic performance of WO3 films with different ITO layers
- 2019
-
Ingår i: EMRS Spring Meeting 2019..
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Electrochromic (EC) materials are able to change their optical properties such as transmission, absorption and reflection reversibly by application of an external voltage. EC metal oxides are divided into two groups: cathodic (coloring under ion insertion) and anodic (coloring under ion extraction). Tungsten oxide (WO3) is a well-known cathodic EC material and has been intensively studied in the last 30 years. EC materials and devices have been developed as an alternative to passive coating materials for light and heat management. Conventionally, an EC device is a construction with five-layers: transparent conducting oxide (TCO)/cathodic EC/ion conducting layer (liquid, gel or solid)/anodic EC/TCO, either all on one substrate or positioned between two substrates in a laminated configuration. Indium-tin oxide (ITO) coated substrates are used as a TCO electrode in EC applications due to their high conductivity and transparency.In this study, we deposited WO3 films onto ITO coated glass substrates with different sheet resistances (15, 30, 60 and 1000 Ω/□) by using DC magnetron sputtering technique. Optical and structural properties of ITO films were investigated. For durability studies, cyclic voltammetry data was recorded for up to 500 cycles between 2.0 and 4.0 V versus Li/Li+ at a scan rate of 20 mV s−1. Chronoamperometry measurements of the WO3 films were also performed. We measured the inserted and extracted charges as well as bleaching and coloring times of WO3 films with different ITO layer properties. Generally, ITO with low resistivity is preferred for the electrochemical measurements while absorption is low in the near-infrared region for ITO with higher resistivity. In this study, it is observed that the ITO with 60 Ω/□ sheet resistance is very suitable for optical and electrochromic measurements.
|
|
| 6. |
- Cindemir, Umut, et al.
(författare)
-
Nickel oxide thin film sensor for fluctuation-enhanced gas sensing of formaldehyde
- 2015
-
Ingår i: 2015 IEEE Sensors. - 9781479982035
-
Konferensbidrag (refereegranskat)abstract
- Nanocrystalline nickel-oxide-based thin films were prepared by advanced reactive gas deposition, and the response of these films to formaldehyde was studied by fluctuation-enhanced sensing. Morphological and structural analyses showed porous deposits of nickel oxide particles with face-centered cubic structure. Resistance fluctuations were measured upon exposure to ethanol, formaldehyde and methane at 200 degrees C. Power density spectra were used to quantify the response. The response to formaldehyde was higher than to ethanol at 200 degrees C, and no significant response was observed for methane thus demonstrating some gas-species selectivity.
|
|
| 7. |
- Ginley, D., et al.
(författare)
-
Transparent Oxides and Related Materials for Electronics and Optics : Phys. Status Solidi A
- 2019
-
Ingår i: physica status solidi (a). - Weinheim : Wiley. - 1862-6300.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The International Symposium on Transparent Oxide Thin Films for Electronics and Optics (TOEO) has been held every two years since 1997. The 10th TOEO conference (TOEO‐10), whose name was changed to The International Symposium on Transparent Oxide and Related Materials for Electronics and Optics so as to include recent related material from TOEO‐8, was held July 3–5, 2017, at International Conference Center, Waseda University, Tokyo, Japan. This conference was very successful and included 105 participants. The TOEO sessions had one special panel discussion on “Energy, the global challenge”, 22 invited talks, 6 contributed oral papers, and 34 poster presentations.We are pleased to publish this special issue of Physica Status Solidi (a). The highest‐quality papers were selected through on‐site review at the conference and by the standard peer‐review process following the criteria of the journal. We expect that this volume will promote the research on transparent oxide materials.The organizers thank Japan Society for the Promotion of Science, the 166th Committee, for continued support.
|
|
| 8. |
- Granqvist, Claes G., 1946-, et al.
(författare)
-
Advances in electrochromic device technology : Multiple roads towards superior durability
- 2019
-
Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 357, s. 619-625
-
Tidskriftsartikel (refereegranskat)abstract
- Most electrochromic (EC) devices must have a service lifetime of many years, and this is particularly so for “smart windows” in buildings with good energy efficiency and indoor comfort. The central part of oxide-based EC devices contains thin films based on W oxide and Ni oxide together with an interposed electrolyte. Depending on operating conditions, these films may show degradation at a slower or faster pace, and means to prevent or reverse this phenomenon, or as a minimum allow reliable lifetime prediction, have been sought ever since the beginnings of EC technology. Here we survey recent endeavors related to EC films of W oxide and Ni oxide and show that (i) electrochemical pretreatment of films in a liquid electrolyte can significantly improve durability, (ii) electrochemical posttreatment in a liquid electrolyte can rejuvenate degraded films, (iii) mixed oxides can have better durability and optical performance than corresponding pure oxides, and (iv) lifetime prediction is possible.
|
|
| 9. |
- Granqvist, Claes G.
(författare)
-
Recent progress in electrochromics and thermochromics : A brief survey
- 2016
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 614, s. 90-96
-
Tidskriftsartikel (refereegranskat)abstract
- Contemporary architecture is characterized by large glazings, which are able to accomplish good indoors-outdoors contact and daylighting. However, glazings, encompassing windows and glass facades, are challenging with regard to energy efficiency and often lead to excessive solar energy ingress and to large thermal losses, which must be balanced by energy-demanding cooling or heating. Cooling, especially, has grown strongly in importance during recent years. Emerging technologies utilizing thermochromics and electrochromics allow control of the inflow of visible light and solar energy and thereby produce better energy efficiency than traditional glazings employing static solutions. Thermochromic thin films, based on vanadium dioxide, let through less solar energy at high temperature than at low temperature, whereas electrochromic devices include thin films-usually based on tungsten oxide and nickel oxide-that can change their transmittance of solar energy and visible light upon the application of a voltage. It is important that electrochromics, and to some degree thermochromics, can enhance indoor comfort and lead to better living and working conditions. The present brief review covers a number of recent advances in thermochromics and electrochromics with a view to applications in energy-efficient buildings.
|
|
| 10. |
- Granqvist, Claes Göran, 1946-, et al.
(författare)
-
Thermochromic Fenestration Based on VO2 : Finally a Technology of Practical Interest?
- 2016
-
Ingår i: Society Of Vacuum Coaters 59th Annual Technical Conference Proceedings, 2016. - : Society of Vacuum Coaters. ; , s. 62-69
-
Konferensbidrag (refereegranskat)abstract
- Vanadium-dioxide-based thermochromic thin films and nanoparticle composites can have significant transmittance for visible light, Tlum, while they are able to transmit more near-infrared solar radiation at τ < τc than at τ > τc, where τ denotes temperature and τc ≈ 68 °C. It has been understood for many years that these properties are of principle interest for energy efficient fenestration, but the technology has been slow to mature. The present paper summarizes the state of the art of VO2-based thermochromics and points at the many advances that have been made during recent years. Specifically, the paper discusses how to employ doping to adjust τc to room temperature and to increase Tlum, how to use nano materials to enhance the solar energy transmittance modulation and Tlum, and how to prepare nanoparticle composites by sputtering. A brief discussion is given on thermochromic light scattering, which is a recently discovered phenomenon.
|
|
