Organic light emitting diode display

A display device, comprising:

• a substrate;
• a driving transistor over the substrate;
• a blocking layer between a channel region of the driving transistor and the substrate in a sectional view, the blocking layer overlapping the channel region of the driving transistor in a plan view;
• and
• an upper electrode over a gate electrode of the driving transistor, the upper electrode overlapping the channel region of the driving transistor in the plan view, wherein
• the upper electrode and the gate electrode of the driving transistor overlapping each other form a capacitor,
• the upper electrode, a first electrode of the driving transistor, and the blocking layer are electrically connected to each other.