To enhance luminance and to improve reliability by including a light emitting polymer having a specific average molecular weight.
An element contains a light emitting polymer being a polymer having average molecular weight of 50,000 to 90,000 as a light emitting material. The element has an anode, an organic electron hole transport layer, an organic light emitting layer, an organic electron transport layer and a cathode in this order. The light emitting polymer is desirably contained in an organic light emitting layer. Polyvinyl carbazole composed of a repeting unit expressed by the formula is suitable as this light emitting polymer. A light emitting substance different from the light emitting polymer may be newly contained in a light emitting material contained in the organic light emitting layer. In this case, for example, the light emitting substance such as an Eu complex is doped in a polymer by using the light emitting polymer as a host material to thereby change a wavelength of the emitting light obtained from an element.
MIYAMOTO HIROO
IKEDA HITOSHI
