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Double-heterostructure GaAs/GaAlAs light-emitting diodes ͑LEDs͒ have been fabricated with the emitter regions beryllium doped to 2ϫ10 19 and 7ϫ10 19 cm Ϫ3. The 7ϫ10 19 cm Ϫ3 doped emitters have an internal quantum efficiency of 10% and an optical modulation bandwidth of 1.7 GHz. The steady-state optical output power versus the input current shows an(More)
—We report high-speed digital modulation of GaAs–AlGaAs light-emitting diodes. Open eye patterns and bit error rates less than 10 9 were obtained for data rates from 750 Mb/s to 1.7 Gb/s. These results are the first report, to our knowledge, of error-free digital modulation experiments for LEDs at bit rates above 1 Gb/s.
The experimental observations of metallurgical interactions between compound semiconductor substrates and metallic or oxide overlayers have stimulated a new model of Fermi level "pinning" at these interfaces. This model assumes the standard Schottky picture of interface band alignment, but that the interface phases involved are not the pure metal or oxide(More)
—Practical design of high-voltage SiC Schottky recti-fiers requires an understanding of the device physics that affect the key performance parameters. Forward characteristics of SiC Schottky rectifiers follow thermionic emission theory and are relatively well understood. However, the reverse characteristics are not well understood and have not been(More)
The dependence of Schottky barrier formation on surface and interface preparation offers several broad avenues for understanding electronic structure and charge transfer at metal/semiconductor junctions. Interface cathode-and photolumines-cence measurements reveal that electrically active deep levels form at III-V and II-VI compound semiconductor surfaces(More)
The photoexcited carrier lifetimes in ex situ-annealed low temperature growth GaAs are measured with a femtosecond transient absorption experiment. The study encompassed two low temperature growth GaAs films with approximately 0.3% and 0.9% excess arsenic incorporated during growth. The observed lifetimes are found to be a function of the spacing of arsenic(More)
We report the controlled deposition of close-packed monolayer arrays of ϳ5-nm-diam Au clusters within patterned regions on GaAs device layers, thus demonstrating guided self-assembly on a substrate which can provide interesting semiconductor device characteristics. Uniform nanometer scale ordering of the clusters is achieved by a chemical self-assembly(More)
We show that ⑀ 1-Cu 3 Ge forms a low-resistance ohmic contact to n-type GaAs. The ⑀ 1-Cu 3 Ge contact exhibits a planar and abrupt interface and contact resistivity of 6.5ϫ10 Ϫ7 ⍀ cm 2 which is considerably lower than that reported for Ge/Pd and AuGeNi contacts on n-type GaAs with similar doping concentrations ͑ϳ1ϫ10 17 cm Ϫ3 ͒. The contact is electrically(More)
Charge transport in 20–30-Å-thick Bi films is studied by scanning tunneling potentiometry at room temperature. Deposition at Tϭ140 K onto InP-based multilayer substrates leads to flat and continuous films that are subjected to a lateral current density of up to 8ϫ10 6 A/cm 2. We find that scattering at surface defects and grain boundaries gives rise to(More)