Seyoon Lee '12: INTEL Abstract
White Light Emitting Diodes have the potential to replace general incandescent light bulbs. Low cost, longevity, and environmental factors are the major advantages of LEDs in general compared to other light sources. However, white LEDs require certain performance factors such as the correct temperature, efficiency, and installation cost in order to replace the current light bulbs. We use a novel methodology in our white LED that has the potential to solve most of the problems. Our white LED is an inorganic-organic hybrid diode with n-type doped Indium Gallium Nitride and p-type doped polymer F8T2. Unlike other methods that are being studied to create white LEDs, this method can create white light with only one diode which emits both blue and yellow light from each layer of the diode to create white light. Doping the n-layer GaN with Indium in order to alter its bandgap energy enables the device to emit visible blue light rather than ultraviolet light. Furthermore, InGaN was implemented using four multi-quantum wells to increase the blue light intensity because blue light had to penetrate through the polymer layer to be visible. The use of p-type polymer F8T2 does away with the difficulty involved in making inorganic p-type semiconductors. Organic semiconductors are easier and cheaper to produce and can be further improved if the hybrid novel LED can be grown on a transparent substrate or be implemented with a meshed type metal contact to increase the light emission from the sample. Further modification of the device’s Indium alloy percentage and the composition of the organic layer will give better correspondence to true white light.