Light emitting material, method of manufacturing the light emitting material and method of manufacturing light emitting layer

摘要

In an organic EL device 1, when a voltage is applied across an anode 3 and a cathode 5, holes are moved in a hole transport layer 41 and electrons are moved in an electron transport layer 43, and the holes and the electrons are recombined in a light emitting layer 42 to emit light. A light emitting material is used to form the light emitting layer 42. When the light emitting layer 42 is formed using the light emitting material, the light emitting layer contains one or more kinds of metallic impurities, but an amount of a metallic impurity of which content is the largest among the metallic impurities contained in the layer is 2.5 ppm or less, or when the light emitting material is dissolved in a liquid so that the concentration thereof becomes 2.0 wt%, the liquid contains one or more kinds of metallic impurities, but an amount of the metallic impurity of which content is the largest among the metallic impurities contained in the liquid is 50 ppb or less. By using such a light emitting material, the decrease of light-emission luminance of the organic EL device 1 can be suppressed.