  Whereas the Si photonic platform is highly attractive for scalable optical
quantum information processing, it lacks practical solutions for efficient
photon generation. Self-assembled semiconductor quantum dots (QDs) efficiently
emitting photons in the telecom bands ($1460-1625$ nm) allow for heterogeneous
integration with Si. In this work, we report on a novel, robust, and
industry-compatible approach for achieving single-photon emission from InAs/InP
QDs heterogeneously integrated with a Si substrate. As a proof of concept, we
demonstrate a simple vertical emitting device, employing a metallic mirror
beneath the QD emitter, and experimentally obtained photon extraction
efficiencies of $\sim10\%$. Nevertheless, the figures of merit of our
structures are comparable with values previously only achieved for QDs emitting
at shorter wavelength or by applying technically demanding fabrication
processes. Our architecture and the simple fabrication procedure allows for the
demonstration of a single-photon generation with purity $\mathcal{P}>98\%$ at
the liquid helium temperature and $\mathcal{P}=75\%$ at $80$ K.
