Light-Emitting Device, Light-Emitting Appliance, Display Device, Electronic Appliance, and Lighting Device

A light-emitting device comprising a first light-emitting layer and a second light-emitting layer between a pair of electrodes,

• wherein the first light-emitting layer includes a first material and a second material,
• wherein the first material has a function of converting triplet excitation energy into light emission,
• wherein the second material has a function of converting singlet excitation energy into light emission and includes a luminophore and five or more protecting groups,
• wherein the luminophore is a condensed aromatic ring or a condensed heteroaromatic ring,
• wherein the five or more protecting groups each independently have any one of an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 12 carbon atoms,
• wherein light emission is obtained from the second material,
• wherein the second light-emitting layer includes a third material and a fourth material,
• wherein the third material has a function of converting singlet excitation energy into light emission, and
• wherein a triplet excitation energy level of the fourth material is lower than a triplet excitation energy level of the third material.

A light-emitting device comprising a first light-emitting layer and a second light-emitting layer between a pair of electrodes,

• wherein the first light-emitting layer includes a first material and a second material,
• wherein the first material has a function of converting triplet excitation energy into light emission,
• wherein the second material has a function of converting singlet excitation energy into light emission and includes a luminophore and at least four protecting groups,
• wherein the luminophore is a condensed aromatic ring or a condensed heteroaromatic ring,
• wherein the four protecting groups are not directly bonded to the condensed aromatic ring or the condensed heteroaromatic ring,
• wherein the four protecting groups each independently have any one of an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 12 carbon atoms,
• wherein light emission is obtained from the second material,
• wherein the second light-emitting layer includes a third material and a fourth material,
• wherein the third material has a function of converting singlet excitation energy into light emission, and
• wherein a triplet excitation energy level of the fourth material is lower than a triplet excitation energy level of the third material.

A light-emitting device comprising a first light-emitting layer and a second light-emitting layer between a pair of electrodes,

• wherein the first light-emitting layer includes a first material and a second material,
• wherein the first material has a function of converting triplet excitation energy into light emission,
• wherein the second material has a function of converting singlet excitation energy into light emission,
• wherein the second material includes a luminophore and two or more diarylamino groups,
• wherein the luminophore is a condensed aromatic ring or a condensed heteroaromatic ring,
• wherein the condensed aromatic ring or the condensed heteroaromatic ring is bonded to the two or more diarylamino groups,
• wherein aryl groups in the two or more diarylamino groups each independently have at least one protecting group,
• wherein the protecting group has any one of an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 12 carbon atoms,
• wherein light emission is obtained from the second material,
• wherein the second light-emitting layer includes a third material and a fourth material,
• wherein the third material has a function of converting singlet excitation energy into light emission, and
• wherein a triplet excitation energy level of the fourth material is lower than a triplet excitation energy level of the third material.