Temperature dependent studies of InP/InGaAs avalanche photodiodes based on time domain modeling

Using a simplified time domain modeling approach, the temperature dependent performance characteristics, such as multiplication gain, breakdown voltage, -3 dB bandwidth, gain bandwidth product and excess noise factor, have been systematically investigated for InP/InGaAs separate absorption, grading, charge and multiplication avalanche photodiodes as a function of temperature from -50/spl deg/C to 110/spl deg/C. In order to model the -3 dB bandwidth versus gain dependence based on the simplified approach, empirical expressions have been proposed to consider the effects of hole diffusion, hole trapping, RC (resistance-capacitance) and gain-bandwidth product limit together with the fast Fourier transform component of the impulse response from the time domain modeling. The modeling results generally agree with or can explain the corresponding experimental results. The effects of changing material parameters on the modeling results are also discussed. In addition, we have found that E/sub rO/, the average energy loss per collision due to optical phonon scattering at 0 K, plays a dominant role in determining the -3 dB bandwidth near breakdown and the slope of the temperature dependence of the breakdown voltage. Further, the improved performance characteristics at decreased temperatures indicate the potential application prospects of the InP/lnGaAs APDs in low temperature environments.