The storage capacitor 140 may include a lower electrode 144 and an upper electrode 146 overlapping each other in the z direction. A first interlayer insulating layer 105 may be located between the lower electrode 144 and the upper electrode 146.

The first interlayer insulating layer 105, which is a layer having a predetermined dielectric constant, may be an inorganic insulating layer formed of SiON, SiOx, and/or SiNx. The first interlayer insulating layer 105 may be formed to have a single layer structure or a multi-layer structure. As shown in FIG. 3, the storage capacitor 140 may overlap the TFT 130. As shown in FIG. 3, the lower electrode 144 of the storage capacitor 140 may also serve as the gate electrode 136 of the TFT 130. In some implementations, the storage capacitor 140 may not overlap the TFT 130, and the lower electrode 144 may be an independent element separate from the gate electrode 136 of the TFT 130.

The storage capacitor 140 may be covered by a second interlayer insulating layer 107. The second interlayer insulating layer 107 may be an inorganic insulating layer formed of SiON, SiOx, and/or SiNx, and may be formed to have a single layer structure or a multi-layer structure.

The driving voltage line PL may be located on a first organic insulating layer 111. The driving voltage line PL may include aluminum (Al), copper (Cu), or titanium (Ti) and may be formed to have a single layer structure or a multi-layer structure. In an embodiment, the driving voltage line PL may have a multi-layer structure formed of Ti/Al/Ti.