Light Emission from Al0.08Ga0.92As Gunn Device

We report light emission characteristic of a waveguided Al0.08Ga0.92As Gunn Device, which consists of an n =4.6x1017 cm-3 doped Al0.08Ga0.92As active layer sandwiched between the undoped Al0.32Ga0.68As waveguiding layers grown... [ view full abstract ]

We report light emission characteristic of a waveguided Al0.08Ga0.92As Gunn Device, which consists of an n =4.6x1017 cm-3 doped Al0.08Ga0.92As active layer sandwiched between the undoped Al0.32Ga0.68As waveguiding layers grown on a semi-insulating GaAs. The device is fabricated in simple bar geometry with a length of 300 m. The device emits light from both edge and surface when it is biased at an applied electric field of onset of the negative differential resistance (NDR) region via recombination of electrons and holes, generated by impact-ionization process within the traveling high-electric fielddomain, that is, Gunn domains. 1,2. Our results show that, because of impact ionization within the travelling space charge, the intensity of the edge- and surface- emitted light is dependent on applied electric field. At low electric fields, light intensity increases linearly then, as applied electric field reaches threshold of NDR process, increases exponentially. Besides, as applied field is increased, full width at half maximum (FWHM) of emitted light decreases and the FWHM of the edge emission is observed to be narrower.