Thin film transistor and method for manufacturing the same, array substrate and display device

A thin film transistor, comprising:

• a gate;
• an active layer;
• a source including a connecting portion, and a first sub-portion, a second sub-portion, and a third sub-portion that are arranged sequentially, wherein at first ends of the first, second, and third sub-portions, the connecting portion is connected to the first sub-portion, the second sub-portion, and the third sub-portion to form two recesses adjacent to each other, and wherein a distance from a second end of the second sub-portion to the connecting portion is smaller than a distance from an second end of the first sub-portion to the connecting portion and a distance from an second end of the third sub-portion to the connecting portion;
• and
• a drain including a connecting block, and a first drain and a second drain disposed in the two recesses respectively, wherein at least a portion of the connecting block is disposed between the first drain and the second drain, and is connected to the first drain and the second drain.