  Strain engineering is a powerful and widely used strategy for boosting the
performance of electronic and optoelectronic devices. Here, we demonstrate an
approach to tune the photoelectric properties of Platinum sulfide (PtS$_2$) by
using a ferroelectric substrate PMN-PT as the strain generator. It is found
that both the drain current and responsivity of the PtS$_2$ photodetector is
directly coupled to the electrostriction of PMN-PT, showing a high strain-tuned
ratio $10^{3}$, high responsivity up to $6.3\times 10^{3}$ A/W and detectivity
of $9.3\times 10^{12}$ Jones. Additionally, a high photogain $\approx 5\times
10^{5}$ is obtained at a gate voltage Vg = 15 V. Our results provide an
effective method for manipulating electrical properties and optimizing
performance of two dimensional layered (2D) materials based optoelectronic
devices.
