A display device (300a-300c;400a-400c;500a-500b), comprising: a substrate; and a first sub-pixel and a second sub-pixel disposed on the substrate, and the first sub-pixel and the second sub-pixel respectively correspond to two different colors, wherein the first sub-pixel comprises: a first light-emitting element; and a first wavelength conversion layer (321R, 521R) adjacent to the first light-emitting element, wherein a light emitted from the first light-emitting element passes through the first wavelength conversion layer; and wherein the second sub-pixel comprises: a second light-emitting element; and a second wavelength conversion layer (321G, 521G) adjacent to the second light-emitting element, wherein a light emitted from the second light-emitting element passes through the second wavelength conversion layer; wherein a) an area of the first wavelength conversion layer and an area of the second wavelength conversion layer are different; or b) a thickness of the first wavelength conversion layer and a thickness of the second wavelength conversion layer are different; or c) an area and a thickness of the first wavelength conversion layer and an area and a thickness of the second wavelength conversion layer are different; characterized in that a light isolation structure (320, 420) is disposed between the first light-emitting element and the second light-emitting element, wherein the first light-emitting element and the second light-emitting element share an N-type semiconductor layer, and the light isolation structure (320, 420) is extended into the N-type semiconductor layer. a substrate; and a first sub-pixel and a second sub-pixel disposed on the substrate, and the first sub-pixel and the second sub-pixel respectively correspond to two different colors, wherein the first sub-pixel comprises: a first light-emitting element; and a first wavelength conversion layer (321R, 521R) adjacent to the first light-emitting element, wherein a light emitted from the first light-emitting element passes through the first wavelength conversion layer; and wherein the second sub-pixel comprises: a second light-emitting element; and a second wavelength conversion layer (321G, 521G) adjacent to the second light-emitting element, wherein a light emitted from the second light-emitting element passes through the second wavelength conversion layer; wherein a) an area of the first wavelength conversion layer and an area of the second wavelength conversion layer are different; or b) a thickness of the first wavelength conversion layer and a thickness of the second wavelength conversion layer are different; or c) an area and a thickness of the first wavelength conversion layer and an area and a thickness of the second wavelength conversion layer are different; a first light-emitting element; and a first wavelength conversion layer (321R, 521R) adjacent to the first light-emitting element, wherein a light emitted from the first light-emitting element passes through the first wavelength conversion layer; and wherein the second sub-pixel comprises: a second light-emitting element; and a second wavelength conversion layer (321G, 521G) adjacent to the second light-emitting element, wherein a light emitted from the second light-emitting element passes through the second wavelength conversion layer; wherein a) an area of the first wavelength conversion layer and an area of the second wavelength conversion layer are different; or b) a thickness of the first wavelength conversion layer and a thickness of the second wavelength conversion layer are different; or c) an area and a thickness of the first wavelength conversion layer and an area and a thickness of the second wavelength conversion layer are different; a second light-emitting element; and a second wavelength conversion layer (321G, 521G) adjacent to the second light-emitting element, wherein a light emitted from the second light-emitting element passes through the second wavelength conversion layer; wherein a) an area of the first wavelength conversion layer and an area of the second wavelength conversion layer are different; or b) a thickness of the first wavelength conversion layer and a thickness of the second wavelength conversion layer are different; or c) an area and a thickness of the first wavelength conversion layer and an area and a thickness of the second wavelength conversion layer are different; a) an area of the first wavelength conversion layer and an area of the second wavelength conversion layer are different; or b) a thickness of the first wavelength conversion layer and a thickness of the second wavelength conversion layer are different; or c) an area and a thickness of the first wavelength conversion layer and an area and a thickness of the second wavelength conversion layer are different; characterized in that a light isolation structure (320, 420) is disposed between the first light-emitting element and the second light-emitting element, wherein the first light-emitting element and the second light-emitting element share an N-type semiconductor layer, and the light isolation structure (320, 420) is extended into the N-type semiconductor layer.