Display apparatus

A display apparatus comprising:

• a substrate including a display area and a peripheral area outside the display area;
• a pixel circuit disposed in the display area and including a driving thin-film transistor and a switching thin-film transistor, wherein the driving thin-film transistor includes a driving semiconductor layer, and the switching thin-film transistor includes a switching semiconductor layer;
• a display element connected to the pixel circuit;
• and
• a built-in driving circuit portion disposed in the peripheral area and including a first peripheral thin-film transistor including a first peripheral semiconductor layer,
• wherein the driving semiconductor layer and the switching semiconductor layer include a same material and each have a mobility less than a mobility of the first peripheral semiconductor layer and wherein the driving semiconductor layer and the switching semiconductor layer are each thicker than the first peripheral semiconductor layer.