Green energy

Facilitator: Professor, thank you so much for joining us today. First of all, tell us a little bit about the zinc oxide project.

Professor: The zinc oxide project is one where we're looking at improving the efficiency of the light emission properties of that material. This follows on from work that we've previously done on material known as gallium nitride. That work started 10years ago and now has gone completely through from having an idea about how to use this material as efficient light-emitting material, all the way through now so it's a commercial product. This is something that you'll see that's been implemented in a whole range of applications. It's sort of a silent revolution. The standard incandescent bulb that's been around for the past hundred years will become a thing of the past in the next 10 years or so.

Facilitator: Okay, so just explain to me a little bit more about why it is so important.

Professor: Well in terms of lighting, and this is known as solid-state lighting, so this is a device known as a diode and a diode consists of a positive and negative or positive and negative areas. With this material, because of these positive and negative areas, it sets up a little voltage barrier and this voltage barrier, if we apply a voltage to it, it can overcome the electrons, can overcome this barrier and that interaction will produce light. Now the advantage is it does this without producing any heat, so it's a very efficient process compared with, say, an incandescent bulb where 90 per cent of the energy that’s used is lost as heat rather than light. So it's a very low power for a very high brightness.

Facilitator: So how, exactly, would this be used in people's everyday lives?

Professor: Well it's already, now, these light-emitting diode traffic lights have proliferated around the city already. If you go to any traffic lights now you'll basically see that instead of one bulb it's actually comprised of something like 140 LEDs. Now the advantage with this, even though there's 140 of these, that because of their low power consumption that light assembly actually uses one-third less power than a conventional incandescent bulb. Even, for example, these torches or flashlights that we have here, you can see that the incandescent bulbs have been replaced with the LED devices here. The advantage here is this bulb lasts for 10years, so it has a very long lifetime and this is the same sort of technology that will be slowly introduced into domestic lighting. Actually lighting consumes something of the order of 20 per cent of the total power worldwide. So if we can introduce solid-state lighting where we're actually using at least a half, you can see immediately that we have a 10 per cent drop in our power usage which translates to a 10 per cent drop in the production of greenhouse gases.

Facilitator: How does this apply with your research then?

Professor: Well with our work, we work at a very fundamental level, understanding how we can improve the efficiency of this material by growing this material with better quality. This material is all manmade material, so it's grown atom by atom, layer by layer. As part of this process, this process is being continuously refined to make better and better quality materials and so we study the light emission from areas that are a millionth of a millimetre to get a complete understanding of the mechanisms that are involved in producing the light emission.

Facilitator: I imagine that means you have some pretty spectacular machinery.

Professor: Yes, like the one behind me here. This enables us to accelerate electrons to very high speed and inject them into one of these materials, this new advanced materials, into this very small volume and then study how the light is emitted by the various attachments that are sitting on the microscope behind me.

Facilitator: Okay, so let's put that in everyday terms. How long before we see results outside the lab?

Professor: Well, as I said, in terms of the gallium nitride technology that we've been working on for 10 years, that's already there. That's out there. These are now engineering issues to make the product more cost efficient. What we're now working on is a material known as zinc oxide. Zinc oxide has excellent properties, in some sense much better properties than gallium nitride and this is sort of the thrust of our research is trying to understand the optical electrical properties of zinc oxide.

Facilitator: Can you give me a timeframe, a ballpark timeframe?

Professor: Well we're not the only group working on this. There's a lot of groups around the world that are working on this problem and as this technology improves and we can produce more efficient bulbs that use less power and emit more light and also as the scale of production increases, the cost of these will continue to fall. It's very possible that in the next, well certainly in the next 20 years, that there'll be no incandescent sources in use at all.

Facilitator: Professor, thank you so much for your time and taking the time to explain some very complex ideas.

Professor: My pleasure.

Facilitator: Best of luck with your research.

Professor: Thank you very much.