On iterative model of performance of micropixel avalanche photodiodes

Abstract This paper was devoted to the experimental verification of results of the iterative model for micropixel avalanche photodiodes. The avalanche processes initiated by single-photoelectron were studied for single-pixel avalanche photodiodes from two different manufacturers. It was found that the effective capacitance of the pixel calculated from the experimental charge–bias voltage dependence exceeds its terminal capacitance by a factor of two only at low values of resistance of the depletion region, while the maximum voltage drop on the pixel just after quenching of avalanche process equals twice the value of bias overvoltage. At high values of resistance of the depletion region, the voltage drop on the pixel equals the value of bias overvoltage and therefore the gain of the device is effectively reduced by a factor of two.