An exciton is a bound state of an electron and an imaginary particle called an electron hole in an insulator or semiconductor, and such is a Coulomb-correlated electron-hole pair. It is an elementary excitation, or a quasiparticle of a solid. In current research, the bound electron and hole pairs (excitons) provide a means to transport energy without transporting net charge. Since an exciton is a bound state of an electron and a hole, the overall charge for this quasiparticle is zero. Hence it carries no electric current.