本論文係研究利用在成長雙層結構有機發光元件中的有機層時一同通入不同壓力的氮氣來改善元件的發光特性。實驗結果顯示添加氮分子於電子傳輸層中可以將啟動電壓及操作電壓分別降到0.8及4.2伏特。然而，添加氮分子於電洞傳輸層中卻可有效的將元件的發光效率提高至27 cd/A（約原來的八倍大）。又由掃瞄式電子顯微鏡（SEM）來分析放在空氣中48小時後的元件有機層表面，吾人發現摻雜在有機層中的氮分子可以藉著防止水氣和有機材料的化學反應大大地抑制了會造成暗點現象的結晶化圓柱，進而對元件的可靠性及壽命的增進有相當的助益。

此外，吾人亦利用氧氣電漿及熱退火處理來改變ITO透明陽極的表面，並嘗試著去探討兩種不同過程於元件性能之影響。初步發現經由電漿處理後可提升電洞注入效率，而熱退火處理則會因升溫而造成的電洞注入惡化，反而平衡了注入的載子數量，得到和電洞傳輸層參雜氮分子相同的效果。

In this thesis, we improve the photoelectric characteristics of bi-layer organic light-emitting diodes (OLEDs) by introducing N2 gas into thermal chamber to co-deposit with different organic layers. Turn-on and operating voltages are successfully reduced to 0.8V and 4.2V, respectively, with the nitrogen-incorporation into Alq3 (ETL). The same process used to TPD layer (HTL) can strongly promote the electro-luminance efficiency to 27 cd/A, which is about 8 times to the value of OLED without the treatment due to the generation of hole block effect. Additionally, the N2 molecules incorporated into organic layers can avoid the reaction of moisture and organic materials thus suppressing the occurrence of destructive crystalline clusters, which will lead to the phenomenon of dark spots.

Moreover, the oxygen-plasma and O2-annealing pretreatments are employed to modify the surface of ITO anodes and to enhance the hole injection and hence the performance of our devices. O2-annealing pretreatment can induce a hole block effect to improve the balance of holes and electrons. Finally, the hole block effects generated by both O2-annealing and nitrogen incorporation are compared.

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