A rotor blade of a wind turbine, the rotor blade comprising: a leading edge and a blunt trailing edge (203, 509), a suction side and a pressure side between the leading edge and the trailing edge (203, 509), the suction side producing a shear layer when air flows around, wherein the leading edge, the blunt trailing edge (203, 509), the suction side and the pressure side form a reference system in which the leading edge is arranged in front of the trailing edge (203, 509) and the suction side is arranged above the pressure side, and wherein in this reference system a chord direction runs from the leading edge to the trailing edge (203, 509), and a splitter plate (207, 301, 401, 501) disposed at the blunt trailing edge (203, 509) of the rotor blade, the splitter plate (207, 301, 401, 501) comprising: a root edge (302, 402, 502), wherein the root edge (302, 402, 502) is arranged at, in particular along, the trailing edge (203, 509) below a transition of the suction side into the trailing edge (203, 509), an end edge (303, 403, 503), wherein the end edge (303, 403, 503) forms a free edge, and a surface between the root edge (302, 402, 502) and the end edge (303, 403, 503) characterized in that the surface has at least one curved part between the root edge (302, 402, 502) and the end edge (303, 403, 503) and at least a part of the surface lies in the shear layer generated by the suction side. a leading edge and a blunt trailing edge (203, 509), a suction side and a pressure side between the leading edge and the trailing edge (203, 509), the suction side producing a shear layer when air flows around, wherein the leading edge, the blunt trailing edge (203, 509), the suction side and the pressure side form a reference system in which the leading edge is arranged in front of the trailing edge (203, 509) and the suction side is arranged above the pressure side, and wherein in this reference system a chord direction runs from the leading edge to the trailing edge (203, 509), and a splitter plate (207, 301, 401, 501) disposed at the blunt trailing edge (203, 509) of the rotor blade, the splitter plate (207, 301, 401, 501) comprising: a root edge (302, 402, 502), wherein the root edge (302, 402, 502) is arranged at, in particular along, the trailing edge (203, 509) below a transition of the suction side into the trailing edge (203, 509), an end edge (303, 403, 503), wherein the end edge (303, 403, 503) forms a free edge, and a surface between the root edge (302, 402, 502) and the end edge (303, 403, 503) characterized in that the surface has at least one curved part between the root edge (302, 402, 502) and the end edge (303, 403, 503) and at least a part of the surface lies in the shear layer generated by the suction side. a root edge (302, 402, 502), wherein the root edge (302, 402, 502) is arranged at, in particular along, the trailing edge (203, 509) below a transition of the suction side into the trailing edge (203, 509), an end edge (303, 403, 503), wherein the end edge (303, 403, 503) forms a free edge, and a surface between the root edge (302, 402, 502) and the end edge (303, 403, 503) characterized in that the surface has at least one curved part between the root edge (302, 402, 502) and the end edge (303, 403, 503) and at least a part of the surface lies in the shear layer generated by the suction side.