ZnO MESFETs for application to Intelligent Windows
Lead Research Organisation:
University of Liverpool
Department Name: Electrical Engineering and Electronics
Abstract
The central aim of the research is to produce electronic circuits into glass windows for visual display, monitoring and control purposes: 'transparent electronics'. The circuits are made from a very thin semiconductor-like material (ZnO: zinc oxide) and thin metal contacts. The materials are so thin (10's nm) that most of the light passes straight through. Thus 'intelligence' can be built into the window. The material used also offers optical advantages in that is 'low emissivity'; its refractive index serves to enhance the capture of solar energy and reduces the heat loss from the building. The added-value of introducing electronics capability into the glass coatings can open up a new generation of glass windows in buildings, cars and aeroplanes; especially for 'heads-up' displays. The last application is currently available using films containing indium. This is a very expensive material so its replacement with ZnO will bring down the cost and so open up the availabilty of such products. ZnO also has low-toxicity.
The devices we will use are called metal-semiconductor field effect transistor (MESFET). These devices are chosen because they are very simple and easy to fabricate. They also operate at lower voltages than the more commonly used metal-oxide field effect transistor (MOSFET), which is found in computers and phones etc. The use of MESFETs avoids the need to develop a gate oxide technology which is very challenging technologically. The downside is that the digital circuits need to more complicated and so take up more space. However, the footprint of the circuits is less critical that for Si based chips, as the electronics is on large area panels. The project is then concerned with the establishment of a MESFET fabrication process, device design for the intended circuitry and finally design and realisation of basic circuit blocks and gate arrays.
The devices we will use are called metal-semiconductor field effect transistor (MESFET). These devices are chosen because they are very simple and easy to fabricate. They also operate at lower voltages than the more commonly used metal-oxide field effect transistor (MOSFET), which is found in computers and phones etc. The use of MESFETs avoids the need to develop a gate oxide technology which is very challenging technologically. The downside is that the digital circuits need to more complicated and so take up more space. However, the footprint of the circuits is less critical that for Si based chips, as the electronics is on large area panels. The project is then concerned with the establishment of a MESFET fabrication process, device design for the intended circuitry and finally design and realisation of basic circuit blocks and gate arrays.
Planned Impact
The aim of the project is to establish a transparent electronics (TE) device capability on commercial, flat glass substrates, building on an atomic layer deposition, thin-film process already established by the team. The establishment of a circuit framework technology will open the door to further built-in capability such as gas sensors, energy harvesters, most of which have been studied for feasibility in the literature. The pathways to impact look to a number of potential beneficiary and market areas, namely the glass, construction, electronics and electronics materials industries. The basic technology should be transferable to other forms of substrate particularly those used for displays and plastic electronics. The area of 'Green Buildings' is of great interest in the drive to reduce energy consumption and intelligent windows can play a significant part in achieving the aims. The building sector accounts for 42% of the EU (our major trading partner) final energy consumption and about 35% of all greenhouse gas emissions. The inorganic transparent electronics global sector was nearly $76.4 billion in 2010, but is expected to increase to $123 billion in 2015, for a 5-year compound annual growth rate of 10. The reports make clear that with the exception of the transparent conductor space, it is still too early to pick real winners and losers in the transparent electronics materials space so the project is timely as the field is only just opening up. The UK has a strong position in the flat glass industry and the added value of built-in electronics and sensors has the potential for a new generation of intelligent glass. A further major outcome of this project lies in the development of a number of chemical precursors for atomic layer deposition. These precursors will have applications in other market sectors, but in particular the mainstream IT industry and the broader field of thin film nanotechnolgy (photovoltaics, catalysts, plastic electronics and others). SAFC Hitech are a major supplier of precursors and support the project. Equally, Silvaco will benefit from improved knowledge of materials and device properties and parameters. The activity on circuit design will also benefit the organic electronics area where there is a dearth of information and experience.
Publications
Birkett M
(2017)
Atypically small temperature-dependence of the direct band gap in the metastable semiconductor copper nitride Cu 3 N
in Physical Review B
Fang Y
(2020)
Aqueous solution-processed AlOx dielectrics and their biased radiation response investigated by an on-site technique
in Radiation Physics and Chemistry
Fang Y
(2019)
Bias-stress stability and radiation response of solution-processed AlOx dielectrics investigated by on-site measurements
in Microelectronic Engineering
Fang Y
(2022)
A promising method to improve the bias-stress and biased-radiation-stress stabilities of solution-processed AlOx thin films
in Radiation Physics and Chemistry
Hall S
(2016)
ZnO MESFETS for application to Intelligent Windows
in Impact
Hall S (invited)
(2015)
Zinc oxide based transparent electronics
Jin J
(2017)
Schottky Diodes on ZnO Thin Films Grown by Plasma-Enhanced Atomic Layer Deposition
in IEEE Transactions on Electron Devices
Jin J
(2016)
Effects of annealing conditions on resistive switching characteristics of SnOx thin films
in Journal of Alloys and Compounds
Jin J
(2018)
A high speed PE-ALD ZnO Schottky diode rectifier with low interface-state density
in Journal of Physics D: Applied Physics
Liu Q
(2021)
Ecofriendly Solution-Combustion-Processed Thin-Film Transistors for Synaptic Emulation and Neuromorphic Computing.
in ACS applied materials & interfaces
Liu Q
(2020)
Comproportionation Reaction Synthesis to Realize High-Performance Water-Induced Metal-Oxide Thin-Film Transistors
in Advanced Electronic Materials
Liu Q
(2022)
All-in-one metal-oxide heterojunction artificial synapses for visual sensory and neuromorphic computing systems
in Nano Energy
Mitrovic IZ
(2018)
Zinc oxide based transparent electronics (Invited)
Phillips L
(2016)
Maximizing the optical performance of planar CH3NH3PbI3 hybrid perovskite heterojunction stacks
in Solar Energy Materials and Solar Cells
Shaw A
(2015)
Characterisation and modelling of Mg doped ZnO TFTs
Shaw A
(2016)
Atomic layer deposition of Nb-doped ZnO for thin film transistors
in Applied Physics Letters
Shaw A
(2017)
Extraction of the sub-band gap density of states of Nb doped ZnO thin film transistors using C-V measurements
in Microelectronic Engineering
Shaw Andrew
(2018)
Atomic layer deposition zinc oxide devices for transparent electronics
Description | The modification of the semiconductor ZnO by alloying using two different routes, namely Mg and Nb has been exploited to make transparent transistors by the ALD manufacturing process for the first time. These materials are much lower cost, more abundant and more environmentally friendly than existing routes which involve indium and gallium; elements that are toxic with indium expensive and difficult to source. |
Exploitation Route | The research will be exploitable where electronics are built into glass screens (e.g. phones and tablets) or into electronically controlled energy saving glazing, for instance. |
Sectors | Construction Electronics Energy Manufacturing including Industrial Biotechology |
Description | XJTLU, China |
Organisation | Xi'an Jiaotong Liverpool University |
Country | China |
Sector | Academic/University |
PI Contribution | PhD project supervision on nano energy technology and devices |
Collaborator Contribution | Exchange of expertise, sample provision, joint PhD projects |
Impact | There have been several journal and conference papers as well as PhD theses completed. There are 8 PhD thesis completed in 2021/22. Some of the most recent: [1] Y. Sun, R. Yi, Y. Zhao, C. Liu, Y. Yuan, X. Geng, W. Li, Z. Feng, I. Mitrovic, L. Yang, C. Zhao, "Improved pseudocapacitances of supercapacitors based on electrodes of nitrogen-doped Ti3C2Tx nanosheets with in-situ growth of carbon nanotubes", Journal of Alloys and Compounds, vol. 859, pp. 158347 - 1-11 (2021) (DOI: 10.1016/j.jallcom.2020.158347). [2] X. Geng, R. Yi, X. Lin, C. Liu, Y. Sun, Y. Zhao, Y. Li, I. Mitrovic, R. Liu, L. Yang, C. Zhao, "A high conductive TiC-TiO2/SWCNT/S composite with effective polysulfides adsorption for high performance Li-S batteries", Journal of Alloys and Compounds, vol. 851, pp. 156793 -1-10 (2021). (DOI: 10.1016/j.jallcom.2020.156793) C. Liu, "Investigation on the Electrochemical Performance of the Silicon and Germanium Based Lithium-ion Batteries" (PhD Thesis / Dissertation) (2020) |
Start Year | 2012 |
Description | Materials and Nanodevices Forum-10 Dec 2021 |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Dr Mitrovic chaired the forum: "Sustainable Materials and Nanodevices", as part of the eFutures "Electronics for Sustainable Societies" Series on Friday 10th December 2021, 11am-1pm BST, via Zoom. As an ever-greater impetus towards global net zero by 2050, eFutures as a UKRI funded Network+ has offering its support to the cause through the "Electronics for Sustainable Societies" Series. Electronics today is at the cutting edge of technological innovation. The forum entailed seven, thought-provoking, cutting-edge 10-minute talks, spanning oxide materials, sustainable polymers and nanocomposites, nanowires for green energy, 2D materials for energy harvesting, phononic nanostructures, wide band gap semiconductors and in particular recent innovations in SiC MOSFET that underpins Tesla cars. These talks were followed by a round-table panel discussion with all speakers. The forum addressed the broad questions of "What's Next for Materials and Nanodevices" from a sustainability/net zero point of view. |
Year(s) Of Engagement Activity | 2021 |
URL | https://efutures2.com/events-2/upcoming-events/sustainable-materials-nanodevices/ |