We investigate the design and characterization of stacked semiconductor structures, specifically p-NiO on n-ZnO, for achieving a multispectral photo-response. This device is fabricated by depositing a thin film of NiO on ZnO using a simple, low-temperature spray pyrolysis technique. The resulting heterojunction device, formed on a glass substrate at 250 °C and annealed at 500 °C, exhibits visible-blind characteristics and demonstrates remarkable stability for ultraviolet (UV) and infrared (IR) detection with a low dark current of 22 nA. The Ag/p-NiO/n-ZnO/Ag device shows enhanced photo-response only at wavelengths of 253 nm and 900 nm with a quick response time (Tr = 4.6 ms and Td = 20.3 ms). The observed photo-current is attributed to defect-mediated charge transport at the interface. These promising results highlight the potential of p-NiO/n-ZnO heterojunction-based device for applications demanding robust performance as visible blind IR and UV photodetectors.