Preparation Of Zn Or Cl Doped Cu₂O Thin Films And Their Photostability Properties

The crisis of environmental pollution and depletion of traditional fossil fuels are difficult challenges which human beings are facing in the 21 st century.Therefore,sustainable clean energy has attracted great attention all over the world.Wherein the photoelectrochemical water splitting is considered as a simple and effective way to transform solar energy into hydrogen energy.with proper bandgap?about 1.8-2.2 eV?,high optical absorption coefficient,non-toxic and environmentally friendly properties,low cost,long minority carrier diffusion length,a theoretical 18 % solar-to-hydrogen conversion efficiency,thus cuprous oxide?Cu₂O?has extensive prospects for photoelectro-chemical water splitting and some other fields.In this paper,a three-electrode electrochemical deposition systems are used for the preparation and doping of Cu₂O film.Zn:Cu₂O films were fabricated by adding ZnSO₄ into electrolyte,then the crystal structure,surface morphology,bandgap and photoelectrochemical properties were characterized and analyzed.It showed that Zn-doped Cu₂O films exhibited higher photocurrent density than undoped films.When the concentration of ZnSO₄ was 160mM,the corresponding film harvested highest carrier concentration(2.7×10¹⁹/cm³)and photostability?92.97 %?.Cl:Cu₂O films were fabricated by the addition of CuCl₂.The results showed that when the concentration of CuCl₂ in the electrolyte reached 100 m M,it harvested maximum photocurrent density?0.043 mA/cm²?.While 40 mM-Cu₂O film obtained highest carrier concentration(2.92×10²⁰/cm³)and photostability?43.1%?.Finally,UV-visible absorption spectroscopy?UV-Vis?,electrochemical impedance spectroscopy analysis?EIS?,X-ray photoelectron spectroscopy?XPS?,photoluminescence?PL?,Fourier transform infrared spectroscopy?FTIR?and Raman spectroscopy were employed to study the behavior of Zn or Cl doped-Cu₂O.It showed that doping could tailor the structure,surface morphology,increase the charge transfer and lower the recombination of electron-hole,thus improved the photoelectrochemical properties.