Patent ID: 7632579

Claim:
A light emitting element comprising at least a light emitting layer containing a light emitting material and a host material and having a peak emission maximum wavelength of 500 nm or less measured under a fixed d.c. voltage wherein the minimum excitation triplet energy level of said host material is higher than the minimum excitation triplet energy level of said light emitting material, and wherein the peak emission maximum wavelength of 500 nm or less is derived from a transition from the minimum excitation triplet energy of at least one of the components of the light emitting layer to the ground state of said at least one of the components of the light emitting layer, wherein the peak emission maximum wavelength is the maximum for at least one of the components of the light emitting layer, and wherein the minimum excitation triplet energy level of said host material is from 68 kcal/mol to 90 kcal/mol, and wherein the light emitting material is an orthometallated iridium complex.