Fabrication of μLEDS for light fidelity optical transmission

International audienceThe recent years have announced the emergence of novel photonic technologies based on III-nitrides semiconductors. Gathering the progress in materials maturity and the advance in manufacturing process, Solid-State Lighting based upon GaN-based light-emitting diodes (LEDs) has emerged as one the dominant technology for indoor/outdoor lighting as in hospital and transportation. In addition, the opportunity to apply LED for indoor/outdoor communication is a research innovation for the community. We have developed the proper design and the clean room fabrication of micro sized visible LEDs based on InGaN/GaN multiple quantum wells (MQWs) grown on sapphire substrates. A PIN configuration is selected for the design. Global experiments have been conducted by reducing the LED dimension (from 300 to 5μm) to lower the capacitance, the internal electric field of InGaN MQWs and therefore to increase the LED’s emission efficiency. Optical and electrical characterizations of the fabricated samples have performed to extract the cut-off frequency. Measurements are performed under reverse bias both in the dark and under illumination by a laser source. Experimental results have demonstrated that a frequency bandwidth of respectively 300MHz and 1.5GHz could be attain for a 100μm and 25μm size structures