| At present, the development of the solar cells is still restricted by many factors,such as high energy consumption of the raw materials production, high cost of p-njunction fabrication and complicated operation process et al. Therefore, for solvingsuch problems, preparation of new semiconductor materials with excellentoptical properties, by using low temperature, non-toxic, no pollution, and lowenergy consumption chemical method, directly forming p-n junctions with othersemiconductor materials of suitable bandwidth, and followed by assembling theminto the solar cell devices are promising. Silver oxides have attracted increasingattention as potential solar cell materials for photovolatic devices due to their idealbandgap and non-toxicity. We have developed a simple, controllable, roomtemperature, solvent-free, low-cost, dry chemical method to in-situ fabricate silveroxide (AgO and Ag2O) thin films by reacting elemental silver with O3inUVgenerated O3atmosphere. We systematically investigated the effects of relativehumidity, reaction temperature, and silver deposition technique on the formationof silver oxide (AgO or Ag2O) thin films. The effects of temperature, relativehumidity accounted for the formation of silver oxide thin films and thecomposition of the final products. Aiming at clarifying the impact of relativehumidity on the formation of silver oxide, we has carried on thoroughdiscussion of the influence and mechanism of silver oxide thin films growthincluding the action of the ozone, hydroxyl free radicals and reactive oxygenspecies, in combination with related literature.On the basis of the in situ synthesized Ag2O thin film semiconductor, wefabricated a composite film by assembling the broadband gap n-type Bi2O3semiconductor into the film for the first time, forming a novel Bi2O3/Ag2O p-njunction at the interface between two materials. The hybrid film has beenpreliminary tested of photoelectric performance using the electrochemicalworkstation. We found that the Bi2O3/Ag2O heterojunction thin film electrodeexhibited higher photovoltaic performances than the pure Bi2O3thin film, which is attributed to the formation of the p-n heterojunction at the interface betweenn-type Bi2O3and p-type Ag2O.The major innovation of this research work are as follows:(1) The reactionconditions were at low temperatures which were mild, and the reaction processhas no influnce on oxide conductive substrate, convenient operation, controllable,short reaction time and low energy consumption, which were useful to producemass AgxO semiconductor thin film materials at low cost and had the prospect ofmassive laboratory preparation and industrial scale production.(2) Theworkmanship was simple and could be directly into the membrane on the surfaceof the substrate, there was no need of after treatment. The process eliminatedcomplicated synthesis and harsh reaction conditions (e.g. high temperature, highvacuum, high energy input, magnetron or electron beam instrumentation) requiredby most synthetic strategies of the pulse high vacuum thermal evaporationreaction, laser film, and electrochemical film.(3) The as-prepared films hadcontrollable macro geometry, which could be well controlled by sputtering andthermal evaporation of pure silver thin film geometry.(4) By controlling silverfilm thickness, reaction time, temperature, relative humidity and differentsubstrate conditions, the morphology, film thickness, phase and crystal face of theAgxO semiconductor could be controlled very well.(5) We have designed andsuccessfully fabricated a novel inorganic hybrid Ag2O/Bi2O3heterojunction thinfilm for the first time which exhibits significantly improved photocurrentcompared with pure Bi2O3film.In the future, this novel Ag2O/Bi2O3heterojunction thin film could be appliedin bulk heterojunction (BHJ) solar cells and has important significance in solarcells which consist of an donor-acceptor (D-A) structure. |
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