Long wavelength GaAs based hot electron photoemission detectors

Abstract

The increasing rate of telecommunication alters both science and technology, and demands high performance components. Photo detectors are essential components of optoelectronic integrated circuits and fiber optic communication systems. A new family of photodetectors offer high performance along with wavelength selectivity: resonant cavity enhanced (RCE) photodetectors. In this thesis, we present our efforts for design, fabrication and characterization of GaAs/AIGaAs based Schottky photodetectors operating within the first (850 nm) and second (1300 nm) optical communication windows. Epitaxial wafers are designed using transfer matrix method based simulation and are grown with molecular beam epitaxy. The photodetector operating at 840 nm was designed with indium tin oxide (IT O ) Schottky layer for high quantum efficiency. The second photodetector is based on internal photoemission, and is compatible with advanced GaAs process technology. Our aim with this design is high speed operation at the second optical communication window. We measured 20 GHz 3-dB bandwidth with 60% quantum efficiency at 840 nm. We expect 50 GHz 3-dB bandwidth with 0.05% quantum efficiency at 1310 nm