Field effect transistor and method of producing the same

A field effect transistor comprising an organic semiconductor layer composed of a crystallized film of a naphthoporphyrin compound represented by general formula (2):

• wherein R1 and R2 each independently denote at least one selected from the group consisting of hydrogen, halogen, hydroxyl, and alkyl, oxyalkyl, thioalkyl and alkyl ester, each alkyl having 1 to 12 carbon atoms;
• R3 denotes at least one selected from the group consisting of a hydrogen atom and an aryl group;
• and
• M denotes two hydrogen atoms, a metal atom or a metal oxide,
• wherein the crystallized film has crystal grains having a maximum diameter of 1 μm or more.

A field effect transistor comprising an organic semiconductor layer composed of a crystallized layer of a naphthoporphyrin compound represented by general formula (2):

• wherein R1 and R2 each independently denote at least one selected from the group consisting of hydrogen, halogen, hydroxyl and alkyl, oxyalkyl, thioalkyl and alkyl ester, each alkyl those having 1 to 12 carbon atoms;
• R3 denotes at least one selected from the group consisting of a hydrogen atom and an aryl group;
• and M denotes two hydrogen atoms, a metal atom or a metal oxide,
• wherein the crystallized film has a strong absorption at 650 nm or longer.