Fig. 3

a Schematic diagrams illustrating the fabrication process of photovoltaic detector based on p-GeTe/n-Si heterojunction and b the device structure. c–d Temporal photoresponse of the device. e Plots of log(J)-V characteristics of the photovoltaic detector under dark (black line) and different irradiation densities (colored lines). f Plots of R (responsivity)-V and gD^* (detectivity)-V characteristics of the photovoltaic detector