Metal oxide thin film of three-dimensional nano ripple structure, method for preparing same, and organic photovoltaic cell comprising same

The present invention provides a method for preparing a metal oxide thin film of a three-dimensional nano ripple structure, comprising the steps of: preparing a metal oxide solution using a sol-gel method (step 1); coating the upper portion of a first electrode with the metal oxide solution prepared in step 1 (step 2); and heat-treating the coated thin film at 180 to 200 °C (step 3). In addition, the present invention can produce a metal oxide thin film having a three-dimensional nano ripple shape of which the electrical properties are enhanced via a low temperature process, has an effect that a change in the electrical properties of a zinc oxide thin film due to a nitrogen ingredient within the thin film significantly enhances the efficiency of a photovoltaic cell, and has an advantage in that the zinc oxide thin film is applicable to plastic flexible substrates, such as PET and PEN.