LIGHT-EMITTING ELEMENT, DISPLAY DEVICE, ELECTRONIC DEVICE, AND LIGHTING DEVICE

摘要

The present invention relates to a light-emitting device, having material which emits fluorescent light, with high light-emitting efficiency. Provided is the light-emitting device comprising: a pair of electrodes; and an electro-luminescent (EL) layer placed between the electrodes. The EL layer has a light-emitting layer, and the light emitting layer has a host and a guest material. The host material has a difference between singlet/triplet excited energy phases from at least 0eV to at most 0.2eV. The guest material is able to emit fluorescent light. The triplet excited energy phase of the host material is higher than the same of the guest material.