The present disclosure provides a thin film transistor, a display panel and a display device. The thin film transistor includes a semiconductor material layer, a first insulating layer and a gate layer. The semiconductor material layer is at a side of a base substrate, and includes a first channel portion, a first doped portion and a second channel portion sequentially connected. The first insulating layer is at a side of the semiconductor material layer facing away from the base substrate. The gate layer is at a side of the first insulating layer facing away from the semiconductor material layer, and includes a first gate portion and a second gate portion. An orthographic projection of the first gate portion on the base substrate coincides with an orthographic projection of the first channel portion on the base substrate, and the first gate portion is configured to receive a gate driving signal.