Applied Physics Letters · 2003 · 61 citations · 15 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsDopingIii-v SemiconductorsSemiconductor PhysicsSemiconductor Thin FilmsWide Band Gap SemiconductorsWide-bandgap SemiconductorsActivation EnergyConductivityFermi LevelFermi Level PinningGallium NitrideOptical PropertiesSemiconductor CharacterizationTransient Current Spectroscopy
Electrical and optical properties of semi-insulating GaN films with the lower part of the film doped with Fe were studied. The room-temperature sheet resistivity of the films was found to be 2×1010 Ω/square. The activation energy of the dark conductivity was ∼0.5 eV which corresponds to the depth of the dominant electron traps pinning the Fermi level. The concentration of these traps was highest in the Fe-doped portion of the films and was on the order of 3×1016 cm−3. Photoinduced current transient spectroscopy also showed the presence of a high concentration of deeper electron traps with level at EC−0.9 eV and hole traps at EV+0.9 eV. These layers look very promising as insulating buffers for AlGaN/GaN transistor structures.
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The Mn3+/2+ acceptor level in group III nitrides
T. Graf, M. Gjukic, Martin S. Brandt et al. · Applied Physics Letters · 2002 · 212 citations