Sulfide-Inhibiting Growth of Lead Sulfide Rods Array Film from Micron to Nano for NIR Photodetector

In general, the growth rate of lead sulfide (PbS) crystals in the solution is fast, and it is difficult to obtain nanosized structure films without the presence of inhibitors. Herein, highly crystalline 1D single-crystal PbS nanorods array on the graphene substrate is prepared in the solution containing a high-concentration sulfur ion as the inhibitors by electrochemical atomic layer epitaxy (ECALE) method. Meanwhile, the diameter of the PbS array from micrometers to nanometers can be controlled by adjusting the ratio of lead and sulfur. Through polarization studies on graphene substrates, the critical role of Au-thiolate in the vertical growth of PbS nanorod is controlled. Finally, the PbS array-graphene heterostructure photodetector presents an extraordinary photoresponsivity in 1.55 mu m at room temperature.