Self-assembled nanocomposites with a high interface-to-volume ratio offer an opportunity to overcome limitations incurrent technology, where intriguing transport behaviors can betailored by the choice of proper interactions of constituents. Here we integrated metallic perovskite oxide SrRuO₃_wurzite semiconductorZnO nanocomposites to investigate the room-temperaturemetal_insulator transition and its effect on photoresponse. Wedemonstrate that the band structure at the interface can be tunedby controlling the interface-to-volume ratio of the nanocomposites.Photoinduced carrier injection driven by visible light was detected across the nanocomposites. This work shows the charge interaction of the verticallyintegrated multiheterostructures by incorporating a controllable interface-to-volume ratio, which is essential for optimization of the design andfunctionality of electronic devices.