Organic Light Emitting Display Device

An organic light emitting display device, comprising:

• a substrate including a first substrate, a second substrate, and an inorganic insulating layer disposed between the first substrate and the second substrate;
• a first buffer layer on the substrate;
• a first thin film transistor including a first active layer that is formed of a first material and includes a first source region, a first channel region, and a first drain region, a first gate electrode that overlaps the first active layer with a first gate insulating layer interposed therebetween, and a first source electrode and a first drain electrode that are electrically connected to the first active layer;
• a second thin film transistor including a second active layer that is formed of a second material and includes a second source region, a second channel region, and a second drain region, a second gate electrode that overlaps the second active layer with a second gate insulating layer interposed therebetween, and a second source electrode and a second drain electrode that are electrically connected to the second active layer;
• a storage capacitor including a first capacitor electrode that is disposed on the same layer as the first gate electrode, and a second capacitor electrode that overlaps the first capacitor electrode with a first interlayer insulating layer interposed therebetween;
• and
• a light blocking layer overlapping a lower portion of the second active layer and formed on the same layer as the second capacitor electrode,
• wherein steps are formed in the light blocking layer, which block light incident through a lower portion and a side surface of the second channel region.

An organic light emitting display device, comprising:

• a substrate;
• a first thin film transistor on the substrate, the first thin film transistor including a first active layer formed of a first material;
• a second thin film transistor on the substrate, the second thin film transistor including:
• an active layer formed of a second material and including a source region, a channel region, and a drain region,
• a gate insulating layer on the active layer, and
• a gate electrode on the gate insulating layer and overlapping the active layer;
• a light blocking layer overlapping the active layer, the light blocking layer having a first portion below the channel region and a second portion that extends upward to horizontally overlap with at least a part of the active layer.