  Quantum photonics promises significant advances in secure communications,
metrology, sensing and information processing/computation. Single photon
sources are fundamental to this endeavor. However, the lack of high quality
single photon sources remains a significant obstacle. We present here a new
paradigm for the control of single photon emitters (SPEs) and single photon
purity by integrating monolayer WS$_2$ with the organic ferroelectric polymer
poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)). We demonstrate
that the ferroelectric domains in the P(VDF-TrFE) film control the purity of
single photon emission from the adjacent WS$_2$. By switching the ferroelectric
polarization, we reversibly tune the single photon purity between the
semi-classical and quantum light regimes, with single photon purities as high
as 94%. This provides another avenue for modulating and encoding quantum
photonic information, complementing more complex approaches. This novel
multidimensional heterostructure introduces a new avenue for control of quantum
emitters by combining the nonvolatile ferroic properties of a ferroelectric
with the radiative properties of the zero-dimensional atomic scale emitters
embedded in the two-dimensional WS$_2$ semiconductor monolayer.
