An electroluminescent display device includes a display panel having a display area and a non-display area. A planarization layer is over the non-display area. A bank is on the planarization layer. An organic layer and a cathode are on the bank. A trench pattern extends through the cathode and the organic layer. An adhesive layer and an encapsulation substrate are disposed over the cathode. The adhesive layer covers the trench pattern. The adhesive layer is effective to slow a rate of moisture penetration to a side surface of the non-display area, allowing for improvements in reliability and a reduction in bezel width.