A conductive layer, comprising a first TCO layer, a second TCO layer, a third TCO layer and a fourth TCO layer which are stacked. The first TCO layer is prepared in a first atmosphere, and the first atmosphere is a mixed gas of argon and hydrogen; the second TCO layer is prepared in a second atmosphere, the second atmosphere is a mixed gas of argon, hydrogen, and oxygen, a partial pressure gradient of hydrogen is reduced, and a partial pressure gradient of oxygen is increased; the third TCO layer is prepared in a third atmosphere, and the third atmosphere is a mixed gas of argon and oxygen; the fourth TCO layer is prepared in a fourth atmosphere, the fourth atmosphere is a mixed gas of argon and oxygen, and a partial pressure gradient of oxygen is decreased.