High performance of visible-NIR broad spectral photocurrent application of monodisperse PbSe nanocubes decorated on rGO sheets
In this work, the photoresponse performance of monodisperse PbSe nanocubes in the range of visible and near-infrared (NIR) (400-1500 nm) regions was enhanced by reduced graphene oxide (rGO). A simple cost-effective method is presented to synthesize monodisperse PbSe nanocubes (NCs) that are decorated on the rGO sheets. By the addition of PbSe/rGO nanocomposites with different rGO concentrations, pristine PbSe NCs were synthesized with the same method. Microscopy images showed that the size of NCs was smaller than the exciton Bohr radius (46 nm) of PbSe bulk. Therefore, the UV-Vis-IR spectroscopy result revealed that the PbSe/rGO samples had absorption peaks in the NIR region around 1650 nm and showed a blue shift compared to the absorption peak of the PbSe bulk. J-V measurements of the samples indicated that monodisperse PbSe/rGO nanocomposites had a higher resistance than the other samples under dark condition. On the other hand, the resistance of the monodisperse PbSe/rGO nanocomposites decreased under different light source illuminations while the resistance of the other samples was increased under illumination. Photodetector measurements indicated that the monodisperse morphology of the PbSe NCs enhanced the photoresponse speed and photocurrent intensity. In addition, responsivity (R) and detectivity (D*) of the samples were higher in the NIR region.