Investigation of temperature and temporal stability of AlGaAsSb avalanche photodiodes

Since avalanche gain and breakdown voltage in most semiconductor materials change with temperature, instruments utilizing Avalanche Photodiodes (APDs) for their avalanche gains need to incorporate either temperature stabilization or voltage adjustment in the APD operation circuits. In this work we evaluated the temperature and temporal stability of avalanche gain in Al0.85Ga0.15As0.56Sb0.44, a wide bandgap semiconductor lattice-matched to InP substrates. We investigated the temperature and temporal stability of the gain and breakdown voltage at temperatures of 24 °C (room temperature) to 80 °C. The breakdown voltage varies linearly with temperature with a temperature coefficient of 1.60 mV/K. The avalanche gain reduces from 10 to 8.5, a reduction of 15%, when the temperature increases from 24 to 80°C. The temporal stability of gain was recorded when the APD was biased to achieve an avalanche gain of 10. Fluctuations are within ± 0.7% at 24°C, increasing to ± 1.33% at 80°C. The temperature and temporal stability of avalanche gain indicates the potential of using Al0.85Ga0.15As0.56Sb0.44 APDs grown on InP substrates to achieve high tolerance to temperature fluctuation.