  Dual phase xenon detectors are widely used in experimental searches for
galactic darkmatter particles. The origin of single electron backgrounds
following prompt scintillation and proportional scintillation signals in these
detectors is not fully understood, although there has been progress in recent
years. In this paper, we describe single electron backgrounds in ${}^{83m}Kr$
calibration events and their correlation with drift and extraction fields,
using the Particle Identification in Xenon at Yale (PIXeY) dual-phase xenon
time projection chamber. The single electron background induced by the
Fowler-Nordheim (FN) effect is measured, and its electric field dependence is
quantified. The photoionization of grids and impurities by prompt scintillation
and proportional scintillation also contributes to the single electron
background.
