NOISE CHARACTERIZATION AND DEVICE PARAMETER EXTRACTION OF A P-TYPE STRAINED-LAYER QUANTUM-WELL INFRARED PHOTODETECTOR

Dark current noise measurements between 10(1) and 10(5) Hz were carrie d out on a compressively strained p-type InGaAs/AlGaAs quantum-well in frared photodetector as a function of temperature and bias voltage. Th e measured noise can be attributed to number fluctuation noise associa ted with the generation and recombination of holes from and to the qua ntum-well bound states and the extended valence-band states. At low bi as the number fluctuation noise translates into current fluctuation no ise via hole diffusion, where as at higher-bias values the coupling is via the hole drift current component. Our measurements indicate that the field-induced barrier lowering and the Schottky image effect stron gly influence the device characteristics. In addition we observe that the thermally generated heavy holes diffuse, at low fields, on the ave rage to the nearest neighboring quantum well where they subsequently r ecombine. This recombination process is triggered by hole scattering w ith the acceptor centers. (C) 1996 American Institute of Physics.