An organic light-emitting diode (OLED) display is disclosed. In one aspect, the display includes a substrate comprising an emission area, a sensor area, and an opening area. The display also includes an OLED formed in the emission area of the substrate, wherein the OLED comprises an organic light emitting layer interposed between pixel and opposite electrodes, wherein the opposite electrode is configured to firstly reflect light emitted from the intermediate layer. The display further includes a photo sensor formed in the sensor area of the substrate and a partition wall located adjacent to the photo sensor and at least partially surrounding the photo sensor. The partition wall is configured to secondly reflect at least a portion of the first reflected light, and wherein the photo sensor is configured to at least partially absorb the second reflected light.