LIGHT-EMITTING ELEMENT, LIGHT-EMITTING DEVICE, ELECTRONIC DEVICE, LIGHTING DEVICE, AND ORGANIC COMPOUND

摘要

The present invention provides a light emitting device with improved reliability. In addition, provided is a high light-emitting device with high current efficiency (or quantum efficiency). Moreover, provided is a novel dibenzo [f,h] quinoxaline derivative preferably applied to light-emitting device which is one embodiment of the present invention. The light-emitting device comprises an EL layer between a positive electrode and a negative electrode, wherein the EL layer has a light-emitting layer. The light-emitting layer comprises a first organic compound having electron transporting properties and hole transporting properties, a second organic compound having hole transporting properties, and a light-emitting substance. The first organic compound and the second organic compound are a combination which forms an excitation complex. A HOMO level of the first organic compound is lower than a HOMO level of the second organic compound, the difference between the HOMO level of the first organic compound and the HOMO level of the second organic compound is lower than or equal to 0.4 eV.