Direct chemical synthesis of PbS on large-area CVD-graphene for high-performance photovoltaic infrared photo-detectors

•CBD-PbS was successfully deposited on large-area CVD-graphene.•PbS thin film showed good crystallinity and strong preferential growth on graphene.•Post-annealing helped with adhesion of PbS on graphene/glass.•Photocurrent transients from PbS films grown on CVD-graphene were investigated.•Photocurrent overshoots were attributed to charge accumulation at interfaces. The need for bendable, flexible and high performance optoelectronic devices has led to various functional materials/graphene hybridized structures. PbS thin films were successfully synthesized by chemical bath deposition (CBD) method directly on large area CVD-graphene and strong preferential growth of PbS along [200] was obtained. We fabricated vertical type Ti/PbS photovoltaic devices with graphene and discussed their photocurrent transient characteristics. Photocurrent spectra of graphene/Ti/PbS device were recorded at 0 V at various temperatures using a Fourier transform infrared (FTIR) spectrometer.