An organic electroluminescent device comprising: an anode layer A; a light-emitting layer B comprising at least one host material H B and at least one thermally activated delayed fluorescence (TADF) emitter compound E B, wherein the light-emitting layer B does not comprise more than 20 % by weight of an electron transport material ETM D; an exciton quenching layer C comprising at least one emitter compound E C and at least 80 % by weight of at least one electron transport material ETM D; an electron-transport layer D comprising at least one electron transport material ETM D; and a cathode layer K, wherein the layers are arranged in the sequential order in the following order - - - -, wherein optionally one or more additional layers may be present between the anode layer A and the light-emitting layer B, between electron-transport layer D and the cathode layer K, or each between the anode layer A and the light-emitting layer B and between electron-transport layer D and the cathode layer K, wherein the exciton quenching layer C is adjacent to both the light-emitting layer B and the electron-transport layer D, and characterized in that the at least one emitter compound E C has a lowest excited singlet state energy level S1(E C) and the at least one electron transport material ETM D has a lowest excited singlet state energy level S1(ETM D), wherein S 1 ETM D > S 1 E C, wherein the at least one emitter compound E B exhibits an emission with an emission maximum λ max (E B) and a full width at half maximum FWHM(E B) and the at least one emitter compound E C exhibits an emission with an emission maximum λ max (E C) and a full width at half maximum FWHM(E C), wherein λ max E B ≥ λ max E C. an anode layer A; a light-emitting layer B comprising at least one host material H B and at least one thermally activated delayed fluorescence (TADF) emitter compound E B, wherein the light-emitting layer B does not comprise more than 20 % by weight of an electron transport material ETM D; an exciton quenching layer C comprising at least one emitter compound E C and at least 80 % by weight of at least one electron transport material ETM D; an electron-transport layer D comprising at least one electron transport material ETM D; and a cathode layer K, wherein the layers are arranged in the sequential order in the following order - - - -, wherein optionally one or more additional layers may be present between the anode layer A and the light-emitting layer B, between electron-transport layer D and the cathode layer K, or each between the anode layer A and the light-emitting layer B and between electron-transport layer D and the cathode layer K, wherein the exciton quenching layer C is adjacent to both the light-emitting layer B and the electron-transport layer D, and characterized in that the at least one emitter compound E C has a lowest excited singlet state energy level S1(E C) and the at least one electron transport material ETM D has a lowest excited singlet state energy level S1(ETM D), wherein S 1 ETM D > S 1 E C, wherein the at least one emitter compound E B exhibits an emission with an emission maximum λ max (E B) and a full width at half maximum FWHM(E B) and the at least one emitter compound E C exhibits an emission with an emission maximum λ max (E C) and a full width at half maximum FWHM(E C), wherein λ max E B ≥ λ max E C.