Simulation of Al_0.85Ga_0.15As_0.56Sb_0.44 avalanche photodiodes

Area of Science:

• Semiconductor Physics
• Optoelectronics
• Materials Science

Background:

• Alloy semiconductors like AlGaAsSb are crucial for optoelectronic devices.
• Avalanche photodiodes (APDs) require materials with low excess noise factors for efficient near-infrared detection.
• Understanding the electric field dependence of ionization coefficients is vital for APD performance.

Purpose of the Study:

• To develop a validated Monte Carlo model for Al0.85Ga0.15As0.56Sb0.44.
• To determine the electric field dependence of ionization coefficients and threshold energies in this material.
• To provide data for simplified APD simulation models.

Main Methods:

• Development of a Simple Monte Carlo model for Al0.85Ga0.15As0.56Sb0.44.
• Validation of the model using experimental data (capacitance-voltage, avalanche multiplication, excess noise factors) from five APDs.
• Simulation to extract effective ionization coefficients and threshold energies.

Main Results:

• The Monte Carlo model accurately reproduces experimental APD characteristics.
• Effective ionization coefficients and threshold energies were determined for Al0.85Ga0.15As0.56Sb0.44.
• Data covers electric fields from 400-1200 kV.cm-1 at room temperature.

Conclusions:

• The developed model provides crucial insights into AlGaAsSb avalanche properties.
• The obtained ionization coefficients are suitable for use in less complex APD simulation models.
• This work facilitates the design and optimization of near-infrared APDs.