  nEXO is a proposed tonne-scale neutrinoless double beta decay
($0\nu\beta\beta$) experiment using liquid ${}^{136}Xe$ (LXe) in a Time
Projection Chamber (TPC) to read out ionization and scintillation signals.
Between the field cage and the LXe vessel, a layer of LXe ("skin" LXe) is
present, where no ionization signal is collected. Only scintillation photons
are detected, owing to the lack of optical barrier around the field cage. In
this work, we show that the light originating in the skin LXe region can be
used to improve background discrimination by 5% over previous published
estimates. This improvement comes from two elements. First, a fraction of the
$\gamma$-ray background is removed by identifying light from interactions with
an energy deposition in the skin LXe. Second, background from ${}^{222}Rn$
dissolved in the skin LXe can be efficiently rejected by tagging the $\alpha$
decay in the ${}^{214}Bi-{}^{214}Po$ chain in the skin LXe.
