Avalanche Current Measurements in SPADs by Means of Hot-Carrier Luminescence

A growing number of applications require arrays of single-photon avalanche diode (SPAD) detectors with low timing jitter. In order to improve jitter without compromising other performance parameters, a clear understanding of avalanche dynamics and statistics is necessary. In this work, a noninvasive electro-luminescence technique has been employed to investigate the current growing in a SPAD device. The obtained results let us assess, for the first time experimentally, the avalanche spreading speeds and also confirmed our assumption that the current growth pace and its statistics critically depend on the space charge effects.