  In semiconducting materials, electrostatic gating and light illumination are
widely used stimuli to tune the electronic properties of the system. Here, we
show a significant enhancement of photoresponse at the conducting interface of
LaVO3-SrTiO3 under the simultaneous application of light and negative gate bias
voltage, in comparison to their individual application. On the other hand, the
LaVO3-SrTiO3 interface remains largely insensitive to light illumination, when
a positive gate bias voltage is applied. Our X-ray diffractometer, Raman
spectroscopy and photoemission measurements show that unlike the LaAlO3-SrTiO3
interface, migration of oxygen vacancies is not the prime mechanism for the
enhanced photoresponse. Rather, we suggest that the photoresponse of our system
is intrinsic and this intrinsic mechanism is a complex interplay between band
filling, electric field at the interface, strong electron interaction due to
mottness of LaVO3 and modification of conducting channel width.
