Thin film transistor substrate and display device comprising the same

A thin film transistor substrate comprising:

• a first switching thin film transistor on a base substrate;
• and
• a second driving thin film transistor on the base substrate and spaced apart from the first thin film transistor,
• wherein the first switching thin film transistor comprises:
• a first active layer;
• and
• a first gate electrode disposed between the base substrate and the first active layer and at least partially overlapping the first active layer,
• wherein the second driving thin film transistor comprises:
• a second active layer;
• and
• a second gate electrode disposed between the base substrate and the second active layer and at least partially overlapping the second active layer,
• wherein the first gate electrode and the second gate electrode are made of different materials, and
• wherein a hydrogen concentration of the second active layer is higher than a hydrogen concentration of the first active layer.

A thin film transistor substrate comprising:

• a first switching thin film transistor on a base substrate;
• and
• a second driving thin film transistor spaced apart from the first switching thin film transistor,
• wherein the first switching thin film transistor comprises:
• a first active layer;
• a first gate electrode at least partially overlapping the first active layer;
• and
• a first light-blocking layer disposed between the base substrate and the first active layer and overlapping the first active layer,
• wherein the second driving thin film transistor comprises:
• a second active layer;
• a second gate electrode at least partially overlapping the second active layer;
• and
• a second light-blocking layer disposed between the base substrate and the second active layer and overlapping the second active layer,
• wherein the first active layer comprises a first oxide semiconductor material, and the second active layer comprises a second oxide semiconductor material,
• wherein a carrier mobility of the first oxide semiconductor material is greater than a carrier mobility of the second oxide semiconductor material, and
• wherein a thickness of the first light-blocking layer is greater than a thickness of the second light-blocking layer.

A display device comprising:

• a display panel;
• a gate driver mounted on the display panel and including a first switching thin film transistor;
• and
• a pixel driving circuit including the first switching thin film transistor and a second driving thin film transistor,
• wherein the first switching thin film transistor includes:
• a first active layer;
• a first gate electrode at least partially overlapping the first active layer;
• and
• a first light-blocking layer disposed between the base substrate and the first active layer and overlapping the first active layer,
• wherein the second driving thin film transistor includes:
• a second active layer;
• a second gate electrode at least partially overlapping the second active layer;
• and
• a second light-blocking layer disposed between the base substrate and the second active layer and overlapping the second active layer,
• wherein the first light-blocking layer and the second light-blocking layer are made of different materials, and
• wherein a hydrogen concentration of the second active layer is higher than a hydrogen concentration of the first active layer.