Cobalt oxide (Co₃O₄) thin films were fabricated by the drop-dry deposition (DDD) method using an aqueous solution containing Co(NO₃)₂ and NaOH. DDD was performed by dropping the solution on a substrate, heating-drying, and rinsing in water. The as-deposited film was Co(OH)₂, and it was converted to Co₃O₄ by annealing in air. The Raman and x-ray diffraction peaks of Co₃O₄ were observed for the annealed films. We also fabricated Co₃O₄/ZnO heterojunction solar cells with ZnO prepared by the electrochemical deposition method. The heterojunction had rectification properties and a weak photovoltaic response. Thus, DDD is promising for fabricating Co₃O₄ layers, and the Co₃O₄/ZnO heterojunction can be used as a solar cell.

氧化钴 (Co ₃ O ₄ ) 薄膜是通过滴干沉积 (DDD) 方法使用含有 Co(NO ₃ ) ₂和 NaOH 的水溶液制备的。DDD 是通过将溶液滴在基板上、加热干燥并在水中冲洗来进行的。沉积后的薄膜为 Co(OH) ₂，通过在空气中退火将其转化为 Co ₃ O ₄。对于退火膜，观察到Co ₃ O ₄的拉曼和X射线衍射峰。我们还制造了 Co ₃ O ₄/ZnO异质结太阳能电池采用电化学沉积法制备的ZnO。异质结具有整流特性和弱光伏响应。因此，DDD有望用于制作Co ₃ O ₄层，并且Co ₃ O ₄ /ZnO异质结可用作太阳能电池。