| 摘要 |
A light emitting material comprising a conjugated polymer compound (A) containing an aromatic ring in the main chain and a compound (B) showing light emission from the triplet excited state, wherein an energy difference between the vacuum level and the lowest unoccupied orbital (LUMO) level in the ground state, calculated by a computational chemical means, is 1.3 eV or more, or an energy difference between the vacuum level and the lowest unoccupied orbital (LUMO) level in the ground state, experimentally measured, is 2.2 eV or more, in the polymer compound (A), and either the following (Condition 1) or the following (Condition 2) or both of them are satisfied. (Condition 1): Energy (ES<SUB>A0</SUB>) in the ground state of the polymer compound (A), energy (ET<SUB>A</SUB>) in the lowest excited triplet state of the polymer compound (A), energy (ES<SUB>B0</SUB>) in the ground state of the compound (B) and energy (ET<SUB>B</SUB>) in the lowest excited triplet state of the compound (B) satisfy the relation (Eq 1 ): <?in-line-formulae description="In-line Formulae" end="lead"?>ET<SUB>A</SUB>-ES<SUB>A0</SUB>>ET<SUB>B</SUB>-ES<SUB>B0</SUB> (Eq1)<?in-line-formulae description="In-line Formulae" end="tail"?> (Condition 2): The ratio PL<SUB>A</SUB>/PL<SUB>B </SUB>of photoluminescence intensity (PL<SUB>A</SUB>) of the polymer compound (A) to photoluminescence intensity (PL<SUB>B</SUB>) of the compound (B) showing light emission from the triplet excited state is 0.8 or less. |
