A light-emitting transistor device comprising: a substrate; a gate electrode; a channel layer comprising one or more organic sublayers, the one or more organic sublayers comprising: a first sublayer comprising an electron-transporting semiconductor material, a second sublayer comprising a hole-transporting semiconductor material, and a third sublayer comprising an electroluminescent semiconductor material and positioned between the first sublayer and the second sublayer; a gate insulating layer positioned between the gate electrode and the channel layer; and a hole electrode through which positive charge carriers are injected into the channel layer and an electron electrode through which negative charge carriers are injected into the channel layer, the hole electrode and the electron electrode being spaced apart from each other at a planar distance defining the length of a channel region therebetween, the hole electrode being in contact with the second sublayer of the channel layer and the electron electrode being in contact with the first sublayer of the channel layer; wherein the channel layer further comprises a first electrically insulating element positioned between the hole electrode and the first sublayer of the channel layer in an area wherein the hole electrode and the first sublayer overlap each other, and a second electrically insulating element between the electron electrode and the second sublayer of the channel layer in an area wherein the electron electrode and the second sublayer overlap with each other, wherein the first electrically insulating element and the second electrically insulating element individually and in combination do not extend the entire length of the channel region. a substrate; a gate electrode; a channel layer comprising one or more organic sublayers, the one or more organic sublayers comprising: a first sublayer comprising an electron-transporting semiconductor material, a second sublayer comprising a hole-transporting semiconductor material, and a third sublayer comprising an electroluminescent semiconductor material and positioned between the first sublayer and the second sublayer; a first sublayer comprising an electron-transporting semiconductor material, a second sublayer comprising a hole-transporting semiconductor material, and a third sublayer comprising an electroluminescent semiconductor material and positioned between the first sublayer and the second sublayer; a gate insulating layer positioned between the gate electrode and the channel layer; and a hole electrode through which positive charge carriers are injected into the channel layer and an electron electrode through which negative charge carriers are injected into the channel layer, the hole electrode and the electron electrode being spaced apart from each other at a planar distance defining the length of a channel region therebetween, the hole electrode being in contact with the second sublayer of the channel layer and the electron electrode being in contact with the first sublayer of the channel layer; wherein the channel layer further comprises a first electrically insulating element positioned between the hole electrode and the first sublayer of the channel layer in an area wherein the hole electrode and the first sublayer overlap each other, and a second electrically insulating element between the electron electrode and the second sublayer of the channel layer in an area wherein the electron electrode and the second sublayer overlap with each other, wherein the first electrically insulating element and the second electrically insulating element individually and in combination do not extend the entire length of the channel region.