Thin film transistor and display panel employing the same

An optical touch display panel comprising a plurality of pixels each comprising a driving transistor that controls an on and off operation of the display cell, an optical sensing transistor that senses incident light, and a switch transistor that outputs data from the optical sensing transistor, and at least one of the driving transistor, the optical sensing transistor, and the switch transistor comprises:

• a gate;
• a first passivation layer covering the gate;
• a channel layer disposed on the first passivation layer;
• a source disposed on and contacting the first passivation layer and contacting a first side of the channel layer;
• a drain disposed on the first passivation layer and contacting a second side of the channel layer;
• a second passivation layer covering the channel layer, the source, and the drain;
• a first transparent electrode layer disposed on the second passivation layer;
• a second transparent electrode layer disposed on the second passivation layer and spaced apart from the first transparent electrode layer;
• a first transparent conductive via that penetrates the second passivation layer and connects the source and the first transparent electrode layer;
• and
• a second transparent conductive via that penetrates the second passivation layer and connects the drain and the second transparent electrode layer, the second transparent conductive via being spaced apart from the first transparent conductive via along a first direction,
• wherein a cross-sectional area of the gate is larger than a cross-sectional area of the channel layer, the source, and the drain combined, and
• wherein a distance between the first transparent conductive via and the second transparent conductive via is shorter than a width of the gate along the first direction.