Nitride RCLEDs Grown by MBE for POF Applications

Abstract

Data links by means of plastic optical fibres (POF) demand efficient light emitting diodes (LEDs) at 510 nm, the most promising candidate being nitride-based resonant-cavity LEDs (RCLEDs). These devices include InGaN/GaN multiple-quantum-well (MQW) structures, and GaN/AlGaN distributed Bragg reflectors. Molecular beam epitaxy (MBE) offers some advantages for the fabrication of nitride RCLEDs, like high In incorporation in the active region, and control of the interface quality in the mirror. The main steps in the development of nitride-based RCLEDs using radio-frequency plasma-assisted MBE are addressed, with emphasis in a) p-type doping of GaN by MBE; b) the optimisation of growth, the design and characterisation of AlGaN/GaN stacks for a reflector in the micro-cavity; and c) the growth of InGaN layers, InGaN/GaN MQWs, and conventional InGaN LEDs, which are studied by structural, electrical and optical techniques. The design and fabrication of nitride RCLEDs, which satisfy spectral and thermal specifications for POF applications, are finally described.