Controlled in situ fabrication of Ag2O/AgO thin films by a dry chemical route at room temperature for hybrid solar cells

Silver oxides (Ag2O and AgO) have attracted increasing attention as potential solar cell materials for photovoltaic devices due to their ideal bandgap and non-toxicity. In order to eliminate the complicated synthesis and harsh reaction conditions (e.g. high temperature, high vacuum, high energy input, electron beam instrumentation) required by most synthetic strategies, we developed a very facile dry chemical approach to directly prepare AgxO species on the ITO substrate by taking advantage of a UV-O-3 surrounding in a controlled way. We systematically investigated the effects of relative humidity, reaction temperature, and the silver deposition technique on the formation of silver oxide (AgO or Ag2O) thin films. A possible synthetic mechanism for the formation of AgO and Ag2O is proposed. More importantly, we have designed and successfully fabricated novel inorganic hybrid Ag2O/Bi2O3 heterojunction thin films for the first time which exhibit significantly improved photocurrent compared with pure Bi2O3 films.