經由調整主動層厚度改善固態有機白光電化學元件之效率

Abstract

固態有機白光電化學元件由於具有結構簡單、可溶液製程、可使用非活性金屬電極與低功耗等優點，在白光照明的應用上極具潛力，因此為了達到實際應用的需求必須更進一步提升固態有機白光電化學元件的效率，而在改善固態有機白光電化學元件的效率方面，靠近電化學摻雜層的複合區激子猝熄是一大障礙。本文使用了調整主動層厚度的方法來減少激子猝熄，固態有機白光電化學元件在適當加厚主動層厚度的情形下，其複合區可以更接近主動層的中央，因此緩解了激子猝熄而提昇元件效率。在優化元件主動層厚度之後可得到大約11 %的外部量子效率以及20 流明/瓦的功率效率，這是目前固態有機白光電化學元件所發表過文獻中效率最高的。本文的結果證實了修改主動層厚度來避免激子猝熄藉此改善固態有機白光電化學元件效率是一個可行的方法。

Exciton quenching in the recombination zone close to electrochemically doped regions would be one of the bottlenecks for improving device efficiencies of solid-state white light-emitting electrochemical cells (LECs). To further enhance device efficiencies of white LECs for practical applications, we adjust the active-layer thickness to reduce exciton quenching. In white LECs with properly thickened active-layer thickness, the recombination zone can be situated near the center of the active layer, rendering mitigated exciton quenching and thus enhanced device efficiencies. High external quantum efficiencies and power efficiencies of optimized devices reach ca. 11% and 20 lm/W, respectively, which are among the highest reported for white LECs. These results confirm that tailoring the thickness of the active layer to avoid exciton quenching would be a feasible approach to improve device efficiencies of white LECs.