Narrowband infrared (IR) photodetection has become a critical technology for the next generation of smart low-power photodetectors. In this work, we present a device based on a graphene-silicon Schottky junction with narrowband response in the short-wave IR (SWIR) regime. Integrating a photonic crystal (PhC) slab in the device enables a wavelength dependant tailoring of graphene absorption. The devices were characterized by photocurrent measurement, which was enhanced more than two orders of magnitude by the PhC integration. The sharp enhancements obtained can also be predicted by numerical simulation. This approach offers a highly scalable, tunable, CMOS-compatible architecture for narrowband IR photodetection, paving the way for next-generation, low-power IR sensors.