A contact hole may be formed through the first passivation layer 118 to expose the first drain electrode 353 of the first thin film transistor 350. However, the present disclosure is not limited to the above-described condition. A contact hole may be formed through the first passivation layer 118 to expose the first source electrode 352 of the first thin film transistor 350. The first passivation layer 118 may be an organic material layer. For example, the first passivation layer 118 may be made of an organic material such as acryl resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin. Alternatively, the first passivation layer 118 may be constituted by a single layer made of silicon nitride (SiNx) or silicon oxide (SiOx) or multiple layers thereof.
The auxiliary electrode 180 may be disposed on the first passivation layer 118. In addition, the auxiliary electrode 180 may be connected to the first drain electrode 353 of the first thin film transistor 350 via the contact hole of the first passivation layer 118. The auxiliary electrode 180 may electrically connect the first thin film transistor 350 and the first electrode 410 of the light emitting element 400. The auxiliary electrode 180 may be formed by a single layer or multiple layers made of at least one of molybdenum (Mo), copper (Cu), titanium (Ti), aluminum (Al), chromium (Cr), gold (Au), nickel (Ni) or neodymium (Nd) or an alloy thereof. The auxiliary electrode 180 may be made of the same material as the first source electrode 352 and the first drain electrode 353 of the first thin film transistor 350.