ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

摘要

The present invention relates to a composition including a mixture of a first compound with a second compound, wherein the first compound has a chemical structure different from the second compound. Both the first compound and the second compound are organic compounds. At least one of the first compound and the second compound contains at least one less abundant stable isotope element. The first compound has a vaporization temperature of T1 and the second compound has a vaporization temperature of T2, wherein both T1 and T2 are in a range form 100°C to 400°C and the absolute value of T1-T2 is less than 20°C. The first compound has a concentration C1 in the mixture and a concentration C2 in a film formed by depositing the mixture at a deposition rate of 2Å/s on the surface from a predetermined distance of the place where the mixture is vaporized in a high-vacuum deposition system having a chamber base pressure of 1x10^-6Torr to 1x10^-9Torr, wherein the absolute of (C1-C2)/C1 is less than 5%.