A Theoretical Comparison of the Breakdown Behavior of $\hbox {In}_{0.52}\hbox {Al}_{0.48}\hbox {As}$ and InP Near-Infrared Single-Photon Avalanche Photodiodes

We study the breakdown characteristics and timing statistics of InP and In_0.52Al_0.48As single-photon avalanche photodiodes (SPADs) with avalanche widths ranging from 0.2 to 1.0 mum at room temperature using a random ionization path-length model. Our results show that, for a given avalanche width, the breakdown probability of In_0.52Al_0.48As SPADs increases faster with over bias than InP SPADs. When we compared their timing statistics, we observed that, for a given breakdown probability, InP requires a shorter time to reach breakdown and exhibits a smaller timing jitter than In_0.52Al_0.48As. However, due to the lower dark count probability and faster rise in breakdown probability with over bias, In_0.52Al_0.48As SPADs with avalanche widths les 0.5 mum are more suitable for single-photon detection at telecommunication wavelengths than InP SPADs. Moreover, we predict that, in InP SPADs with avalanche widths les 0.3 mum and In_0.52Al_0.48As SPADs with avalanche widths les 0.2 mum, the dark count probability is higher than the photon count probability for all applied biases.