Cheaper electricity with lower carbon emissions – now it's possible

Dramatic changes are taking place in lighting technology thanks to groundbreaking research carried out by Professor Tao Wang from the semiconductor group of the Department of Electronic and Electrical Engineering at the University of Sheffield.

Solid state lighting, mainly based on III-nitride semiconductor blue/green light-emitting diodes (LEDs), has been accepted as ultimate light source in a variety of applications, for example, general illumination, which will eventually replace all incandescent and florescent bulbs currently used. Therefore, III-nitride semiconductor materials and devices have emerged as highly regarded research area. A team in Sheffield, led by Professor Wang, is carrying out the research on III-nitride LEDs in a wide spectral region from green to ultraviolet.

"With the achievement of these techniques, worldwide electricity consumption due to lighting could be decreased, and proportionately carbon emissions and new capital infrastructure associated with electricity generation would decrease as well," says Professor Wang, "it's both effective and environmentally friendly."

In particular, ultraviolet (UV) LEDs are currently becoming more and more attractive due to wide applications in biological area in addition to general illumination. How to achieve III-nitride semiconductor materials with a high crystal quality is one of the challenges in the development of UV-LEDs. The recent research from Professor Wang's team has demonstrated that the crystal quality can be massively improved by so-called "a thin GaN interlayer" growth technique developed by Dr Wang. The thin GaN layer was initially deposited on AIN as a buffer layer, and resulted in greatly improved optical and electrical properties of the 340nm UV-LED.

Compared with the UV-LEDs fabricated using conventional technique, the output power of the UV-LED was significantly increased by more than 220%, meaning that the cost of the energy can be decreased by more than 220%.

"Everyone needs electricity and cheap electricity, so I think the development of this technology can benefit everyone in the UK, even in the world," says Professor Wang, "and it also benefits the environment because using the light effectively can decrease the carbon emission."

Professor Wang went on to add that, "This technology can be applied in other fields, for instance, UV emitters have a variety of applications in biological detection and imaging."

For further information, please contact Professor Tao Wang at:

tel: +44 (0) 114 222 5902

email : t.wang@sheffield.ac.uk