Core-shell nickel-graphene nanoparticles for efficient tin sulfide/polymer bulk hetero-junction solar cells

The Nickel-Graphene core-shell nanoparticles (Ni-GR CSNPs) were synthesized by thermal chemical vapor deposition (T-CVD) method. The prepared materials were characterized by different physicochemical techniques. The sizes of the Ni−GR NPs are in the range of approximately 60–200 nm as measured from the outermost graphene layer. The Ni-GR CSNPs were incorporated to the device’s photoactive layer, which supporting electron transfer faster by the charge selective graphene and the extraction of electrons prevented the recombination of holes and electrons. The surface roughness of photoactive layer was controlled by inserting a thin layer of ZnO with different thickness between the photoactive layer and the back contact. Finally, the device with the structure of glass/indium tin oxide (ITO)/(polyethylene dioxy thiophene doped with polystyrene-sulfonic acid (PEDOT:PSS)/SnS + PTB7 + Ni-GR CSNPs/zinc oxide (ZnO)/E-GaIn showed a power conversion efficiency (PCE) of ~ 3.2%.