Preparation of graphene films bridged with Ag nanowires and its application in heterojunction solar cells

In this work, efforts were made to further improve the performance of heterojunction solar cells based on graphene films. A dip-drawing method was developed to synthesize the Ag nanowires/graphene composite film (Ag NWs/G). Then, Ag nanowires were superimposed on the single layer graphene and was used as an upper electrode of the solar cell. As expected, this combination has taken advantage of the high carrier concentration of Ag nanowires and high carrier mobility of graphene. Ag NWs/G composite films with high conductivity and transmittance were obtained. The Raman spectral characterization verified the typical feature of graphene films. And, the effect of Ag nanowires on graphene film was demonstrated. Ag nanowires can effectively reduce the resistivity of graphene films, thus solve the problem of carrier recombination. Efficiency of 8.74% was achieved for Ag NWs/G film based solar cells without any antireflective coatings. The modification roles of the Ag NWs/G film in solar cell were discussed. It was verified that the superposition of Ag nanowires can highly facilitate the transmission of current. As a whole, the Ag NWs/G composite film with high transmittance and low square resistance will be more suitable as a transparent electrode, as well as a function layer.