  Scalable quantum photonic architectures demand highly efficient, high-purity
single-photon sources, which can be frequency matched via external tuning. We
demonstrate a single-photon source based on an InAs quantum dot embedded in a
micropillar resonator, which is frequency tunable via externally-applied
stress. Our platform combines the advantages of a Bragg micropillar cavity and
the piezo-strain-tuning technique enabling single photon spontaneous emission
enhancement via the Purcell effect and quantum dot (QD) with tunable
wavelength. Our optomechanical platform has been implemented by integration of
semiconductor-based QD-micropillars on a piezoelectric substrate. The
fabricated device exhibits spontaneous emission enhancement with a Purcell
factor of 4.4$\pm$0.7 and allows for a pure triggered single-photon generation
with $g^{(2)}(0)$ < 0.07 under resonant excitation. A quantum dot emission
energy tuning range of 0.75 meV for 27 kV/cm applied to the piezo substrate has
been achieved. Our results pave the way towards the scalable implementation of
single-photon quantum photonic technologies using optoelectronic devices.
