有机半导体非平衡态HOMO和LUMO能量位移规律与OLED中“热激子”形成的唯象理解

Extent and Changeable Rule of HOMO and LUMO Energy of Organic Semiconductors in Nonequilibrium States and a Phenomenological Understanding for the Formation of“Hot Excitons”in OLED

以能斯特方程为基础,通过分析电流密度与氧化还原物种活度变化,即载流子浓度变化的关系,计算出有机半导体材料电极电势的变化,从而建立起有机半导体前线轨道,即最高占据分子轨道(HOMO)能级和最低未被占据分子轨道(LUMO)能级相对于热力学平衡态的能量位移随电流密度变化的数学关系.进而依据能级能量位移引起的能隙变化,提出了有机电致发光显示器(OLED)中“热激子”的产生机制.

Based on Nernst equation,the change of electrode potential of organic semiconductor materials was calculated through the relationship between current density and redox species activity,i.e.,the change of carrier concentration,so as to establish the mathematical relationship between the energy displacement of their front-line orbit,the highest occupied molecular orbital(HOMO)energy level and the lowest unoccupied molecular orbital(LUMO)energy level relative to the thermodynamic equilibrium state with the current density.Moreover,through the energy gap change caused by the energy level energy displacement,the generation mechanism of thermal exciton in OLED was proposed.