Semiconductor device and method of manufacturing thereof

An electronic device comprising:

• a printed wiring board;
• a display panel connected to and formed over the printed wiring board;
• an integrated circuit connected to and formed over the printed wiring board;
• and
• an optical sensor connected to the printed wiring board and formed over the integrated circuit,
• wherein the optical sensor comprises a flexible substrate, a thin film transistor formed over the flexible substrate, and a semiconductor element formed over the thin film transistor,
• wherein the thin film transistor comprises a crystalline semiconductor film, a gate electrode formed over the crystalline semiconductor film, and a source electrode and a drain electrode which are connected to and formed over the crystalline semiconductor film,
• wherein the semiconductor element comprises a first electrode, a semiconductor film formed over the first electrode, and a second electrode formed over the semiconductor film,
• wherein the optical sensor further comprises a wiring layer which electrically connects the gate electrode of the thin film transistor to the first electrode of the semiconductor element, and
• wherein the semiconductor film of the semiconductor element is located above the crystalline semiconductor film of the thin film transistor.