Search

Monte Carlo is used to model the electric field and temperature dependence of the electron ionization coefficient, α, in In0.53Ga0.47As, using a two-component ionization rate to account for its observed anomalous dependence on the electric field. α is predicted to decrease with temperature at fields above approximately 180 kV/cm, where impact ionization is limited by the high-energy electron population, and to increase with temperature at lower fields, where it is enhanced by the decreasing ionization threshold energy, in agreement with experimental observations.

Electron multiplication for a series of In0.53Ga0.47As p-i-n diodes and hole multiplication for a n-i-p diode were measured at electric fields of 100–260 kV/cm over a temperature range of 20–300 K. The electron multiplication characteristics consistently showed positive temperature dependence at low electric fields (below ∼200 kV/cm) but exhibited negative temperature dependence at high fields. These observations explain the apparent discrepancies of the temperature dependence of the electron ionization coefficient in In0.53Ga0.47As in literature. In contrast, hole multiplication showed little change with temperature.

We show that the n-type conductivity of the narrow band gap In(AsN) alloy can be increased within a thin (similar to 100 nm) channel below the surface by the controlled incorporation of H-atoms. This channel has a large electron sheet density of similar to 10(18) m(-2) and a high electron mobility (mu > 0.1 m(2)V(-1)s(-1) at low and room temperature). For a fixed dose of impinging H-atoms, its width decreases with the increase in concentration of N-atoms that act as H-traps thus forming N-H donor complexes near the surface. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

An Indium Arsenide Bismide photodiode has been grown, fabricated, and characterized to evaluate its performance in the Mid Wave Infrared region of the spectrum. Spectral response from the diode has been obtained up to a diode temperature of 225 K. At this temperature, the diode has a cut off wavelength of 3.95 μm, compared to 3.41 μm in a reference Indium Arsenide diode, indicating that Bismuth has been incorporated to reduce the band gap of Indium Arsenide by 75 meV. Similar band gap reduction was deduced from the cut off wavelength comparison at 77 K. From the dark current data, shunt resistance values of 8 and 39 Ω at temperatures of 77 and 290 K, respectively, were obtained in our photodiode.

An experimental investigation into impact ionization in InAs photodiodes is presented. Photomultiplication measurements on p-i-n and n-i-p diodes show that while high avalanche gains can be obtained for electron initiated multiplication, there is virtually no gain with hole initiated multiplication. This indicates that the electron ionization coefficient is significantly greater than the hole ionization coefficient raising the possibility of extremely low noise InAs avalanche photodiodes when gain is initiated by electrons. The onset of electron initiated impact ionization was detectable at electric fields below 10kVcm−1 with useful gain observed at biases below 10V.