  Silicon photomultipliers (SiPMs) are solid-state, single-photon sensitive,
pixelated sensors whose usage for scintillation detection has rapidly increased
over the past decade. It is known that the avalanche process within the device,
which renders a single photon detectable, can also generate secondary photons
which may be detected by a separate device. This effect, known as external
crosstalk, could potentially degrade the science goals of future xenon dark
matter experiments. In this article, we measure the effect of external
crosstalk in a dual-phase, liquid xenon time projection chamber fully
instrumented with SiPMs. We then consider the implications for a future xenon
dark matter experiment utilizing SiPMs and discuss possible solutions.
