ZnO MESFETs for application to Intelligent Windows

点击翻译按钮获取中文摘要

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.