Method for surface modification of copper indium gallium diselenide (Cu(In, Ga)Se2) film
The invention discloses a method for surface modification of a copper indium gallium diselenide (Cu(In, Ga)Se2) film and relates to the technical field of photoelectric function materials and new energy. The method is characterized by comprising the following steps: depositing a metal film or an alloy film with a certain thickness on the (Cu(In, Ga)Se2) film, performing high temperature annealing on the (Cu(In, Ga)Se2) film under reactive atmosphere and carrying out a copper selenium secondary phase (CuxSe) reaction on the surface of the deposited metal or alloy and (Cu(In, Ga)Se2) film to form a copper selenium poly-metal compound with a wide band gap so as to fulfill the aim of removing CuxSe. By the surface modification method, the defect that toxicity exists and the environment cannot be protected in etching the CuxSe by the traditional modification method by adopting KCN (potassium cyanide) are overcome; the method has the advantages of being low in cost and high in reproducibility and being suitable for large-area film growth and the like; and with the adoption of method, the band gap width on the surface of the film can be improved, a gradient band gap is formed, the pn junction interface composition is obviously reduced, and the open-circuit voltage of a device is effectively improved.