A method for manufacturing a quantum dots layer including providing a substrate on which a first electrode, a second electrode, and a third electrode are disposed; providing a first mixed solution including a first quantum dots, which have been surface-treated to have a first polarity, on the first to third electrodes; providing a second polarity opposite to the first polarity to the first electrode resulting in deposition of the first quantum dots on the first electrode; and drying the first mixed solution to form a first quantum dots layer.