Can we design efficient red LEDs? Holonyak at GE mixed Ga+As+P – made red LED efficiency 0.1 c.f. Edison 2 Modern bulb 17 1970 GaAsP LED efficiency = 0.2 1980 AlGaAs/GaAs LED efficiency = 2 1990 AlInGaP/GaAs LED efficiency = 10 2000 AlInGaP/GaP LED efficiency = 100 10 times...
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Applications of LEDs Replacing neon signs Traffic signs on highways VW dashboard lighting Full colour displays – Times Square, New York – tens of metres high – use millions of LEDs – display real-time videos Domestic and office lighting? Previous slide Next slide Back to first slide View graphic...
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LEDs Light emitting diodes Made from solids that emit light LEDs last 100,000 hours Light bulbs last 1,000 hours LEDs fail by slow intensity decrease Light bulbs fail totally and suddenly Previous slide Next slide Back to first slide View graphic version
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The LED Story LED vs incandescent bulb Previous slide Next slide Back to first slide View graphic version
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The Need: Ultra-efficient Lighting 20% of all electricity consumption in the UK is for lighting In Thailand over 40% is for lighting Can we use materials science to design ultra-efficient lighting? Previous slide Next slide Back to first slide View graphic version
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GaN Electronic Devices Market in 2000 = $0 Market in 2010 = $500m forecast Mainly high-frequency high-power amplifiers (HEMTs) for wireless base stations, satellite ground terminals Also power switches High T – Oil, cars, aero Previous slide Next slide Back to first slide View graphic version
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GaN LED Market Year 1995 1996 1997 1998 1999 2009 Market in $ Million 30 80 110 210 420 2440 (prediction) 1995 – 1999: Compound Annual Growth 79% p.a. 1999 – 2009: Predicted growth 20% p.a. Previous slide Next slide Back to first slide View graphic version
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Integration of III-nitrides with Silicon MEM Technology Microelectromechanical devices integrating mechanical elements, sensors, actuators and electronics on a common silicon substrate through the utilisation of microfabrication technology. 1.4m II-V semiconductor processing cluster tool for GaN microfabrication: Reactive ion etching CVD dielectrics PVD metallisation Support of STS Ltd is gratefully...
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Integration of III-nitrides with Silicon MEM Technology Research includes: Buffer layer development for GaN growth on Si(111) and Si (100) Mask and etches for GaN/Si Evaluation of GaN peizoelectric sensor properties Support of AEA Technology is gratefully acknowledged Cantilever test structure for accelerometer Previous slide Next slide Back to...
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