An investigation of photovoltaic devices based on p‐type Cu2O and n‐type γ‐WO3 junction through an electrolyte solution containing a redox pair

In this article, we report a solar cell prepared with p-type cuprous oxide (Cu2O) and n-type gamma-tungsten oxide (γ-WO3) films combined by an redox electrolyte in a configuration similar to that used in dye-sensitized solar cells. Cu2O films were prepared by the electrochemical method in three different pH conditions. X-ray diffraction patterns revealed that the Cu2O films presented a crystalline phase with cubic structure after deposition, whereas the n-type γ-WO3 film was prepared by the drop-casting method. Optical analyses showed that both oxide films absorb visible light. After the photoelectrochemical characterization of the films, solar cells configured like a “sandwich” (Cu2O/electrolyte/γ-WO3) were assembled and investigated under irradiation of 100 mW cm−2. The solar cell with I−/ redox pair showed better results than that prepared with polysulfide K2S/ electrolyte. For each solar cell, the investigated parameters were short-circuit current density, open-circuit voltage, fill factor, maximum power, and cell efficiency. The method proposed here can be considered new, promising, and simple for the preparation of solar cells with a p–n junction.