A spacer 190 may be on the pixel defining layer 180. The spacer 190 may prevent damage to the organic light-emitting diode OLED due to sagging of a mask in a manufacturing process in which the mask may be used. The spacer 190 may include, for example, an organic insulating material such as polyimide, polyamide, an acrylic resin, benzocyclobutene, hexamethyldisiloxane (HMDSO), and a phenol resin, or a combination thereof, and may be obtained by spin coating, or the like. The spacer 190 may have a single-layered or multi-layered structure.

The intermediate layer 220 may be on the pixel electrode 210 that may be exposed via the pixel defining layer 180. The intermediate layer 220 may include a light-emitting layer, and functional layers such as a hole transport layer (HTL), a hole injection layer (HIL), an electron transport layer (ETL), and an electron injection layer (EIL) may be selectively arranged under and on the light-emitting layer.

The light-emitting layer may include an organic material including a fluorescent or phosphor material emitting red light, green light, blue light, or white light. The light-emitting layer may include low-molecular weight organic materials or polymer organic materials.

In case that the light-emitting layer includes a low-molecular weight organic material, the intermediate layer 220 may include an HIL, an HTL, an emission layer (EML), an ETL, and an EIL in a single or multiple-layered structure. Examples of the low-molecular weight material may include copper phthalocyanine (CuPc), N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), and tris-8-hydroxyquinoline aluminum (Alq₃). The above layers may be manufactured, e.g., by a vacuum deposition method.