The application relates to a strongly-polarized molecule of the following general formula: wherein A denotes a group having a polarizability greater than 2 C.Math.m.sup.2/V; R.sub.1 and R.sub.2 are respectively hydrogen, halogen, a hydroxyl group, an amino group, a cyano group, a nitro group, a carboxyl group, a C.sub.1-12 alkyl group, a C.sub.1-12 alkoxy group, a halogenated C.sub.1-12 alkyl group, a halogenated C.sub.1-12 alkoxy group, a hydroxyl C.sub.1-12 alkyl group, a hydroxyl C.sub.1-12 alkoxy group, or a C.sub.1-12 alkyl amino group; x.sub.1 and x.sub.2 denote 0 or an integer no less than 1, respectively; and y.sub.1 and y.sub.2 denote 0 or an integer no less than 1, respectively. The application further relates to a strongly-polarized molecule-graphene molecule heterojunction, and a single molecule field effect transistor comprising a substrate, a gate, a dielectric layer and the strongly-polarized molecule-graphene molecule heterojunction; and the dielectric layer is located between the gate and the strongly-polarized molecule-graphene molecule heterojunction. The single molecule field effect transistor provided by the application can realize highly-efficient gate modulation. ##STR00001##

A novel organometallic complex which can emit phosphorescence is provided. A light-emitting element, a light-emitting device, an electronic device, or a lighting device with high emission efficiency is provided. The organometallic complex having an aryl triazine derivative as a ligand is represented by General Formula (G1) below as a representative of the organometallic complex of the present invention. ##STR00001##