  In this paper, we report a novel photovoltaic phenomenon in a low cost
manganite/ZnO p-n heterojunction grown on ITO glass substrate by pulsed laser
depositon (PLD) under relative low growth temperature. The heterostructure
ITO/La0.62Ca0.29K0.09MnO3(LCKMO)/ZnO/Al exhibits reproducible rectifying
characteristics and consists of four parts: aluminum top electrode, ITO bottom
electrode, manganite and ZnO semiconductor films. Moreover, the light current
can generate under continuous laser ({\lambda}=325nm) irradiation. In this
article, we investigate the influence of manganite and ZnO film thickness on
the electrical and photoelectric characteristics of the heterostructure at room
temperature. The maximum power conversion efficiency (PCE) is achieved not only
when the LCKMO and ZnO layer is thin enough, but also when the full space
charge layer is sufficient. We obtain the maximum value(0.0145%) of PCE when
the thickness of LCKMO and ZnO layer is 25nm and 150nm, respectively. Under
this condition, the open circuit voltage is 0.04V, which can be attributed to
internal photoemission.
