Light-emitting element, display device, electronic device, organic compound, and lighting device

A light-emitting element comprising:

• a light-emitting layer between a pair of electrodes, the light-emitting layer comprising:
• a first material capable of converting triplet excitation energy into light emission;
• and
• a second material capable of converting singlet excitation energy into light emission,
• wherein the second material comprises a luminophore and a first protecting group, a second protecting group, a third protecting group and a fourth protecting group,
• wherein the luminophore is a condensed aromatic ring or a condensed heteroaromatic ring,
• wherein each of the first protecting group, the second protecting group, the third protecting group and the fourth protecting group is not directly bonded to the condensed aromatic ring or the condensed heteroaromatic ring,
• wherein each of the first protecting group, the second protecting group, the third protecting group and the fourth protecting group independently comprises 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 an emission spectrum of the first material overlaps with an absorption band on the longest wavelength side of an absorption spectrum of the second material, and
• wherein a T1 level of the second material is lower than a T1 level of the first material.

A light-emitting element comprising:

• a light-emitting layer between a pair of electrodes, the light-emitting layer comprising:
• a first material capable of converting triplet excitation energy into light emission;
• and
• a second material capable of converting singlet excitation energy into light emission,
• wherein the second material comprises a luminophore and five or more protecting groups,
• wherein the luminophore is a condensed aromatic ring or a condensed heteroaromatic ring,
• wherein each of the five or more protecting groups independently comprises 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 first material comprises a compound emitting phosphorescence, and
• wherein a T1 level of the second material is lower than a T1 level of the first material.