透過微共振腔內部的光學現象，可以使材料發光光譜從較廣的範圍縮減至較窄的範圍，代表材料內部激發態的能量受到共振腔而改變，且在先前的論文中提到在微共振腔結構下的磁場效應有被增強的趨勢，因此想探討微共振腔元件磁場效應中的主導機制。
本篇論文將常見的高分子材料PPV的衍生物Super-yellow(SY-PPV)做為微共振腔元件的主動層材料，透過改變銀陰極的厚度調變元件的發光光譜半高寬，可以從原本約100 nm的半高寬縮減至約20 nm，接著將微共振腔元件置於外加磁場的環境中量測磁場下的電致發光變化，並發現磁電致發光效應會隨著共振腔模態場變化，便是由於共振腔增加了分子間交互作用(Intermolecular interaction)所造成的現象。
於是，便透過增加通過元件的電流密度以減少載子間的距離增加彼此間的交互作用，以驗證增加分子間交互作用是否會改變磁場效應，並且從共振腔模態場寬與窄的元件磁效應中發現，共振腔模態場較窄的元件在較小的電流密度變化就可以有較大的磁場效應變化，如此便可以得知增加分子間交互作用進而改變磁場效應的首要影響為共振腔模態場，次要影響則是電流密度的變化。
最後我們使用聚芴的衍生物(polyfluorene derivative, PF)驗證我們的理論機制不只在一個高分子材料出現，也可以在不同的主動層材料中有相同的機制存在，且根據論文的回顧發現PF具有較為明顯的三重態湮滅(Triplet-triplet annihilation, TTA)的現象，驗證共振腔提升分子間交互作用的理論。

In this work, we observe the device with microcavity structure will have different magnetoelectroluminescence (MEL) line-shape comparing to device without microcavity. Trough microcavity effect we can get narrower emission spectral and higher optical confinement. We use light-emitting polymer super-yellow (SY-PPV) as active material in microcavity device. It has been well known the spin reaction process of SY-PPV happens in polaron pair system by using magnetic field effect. The spin in polaron pairs can easily be flipped by the magnetic field energy. Therefore, we can observe the ratio between singlet and triplet polaron pairs (PPS and PPt). In microcavity device, we can observe different line-shape of MEL and the full wavelength at half maximum (FWHM) of line-shape be narrowed while the thickness of semitransparent cathode increased. The change of the emission spectral and MEL is due to the redistribution of spatial energy in SY-PPV. It will affect the spin exchange interaction in polaron pairs. Higher carrier concentration will also affect spin exchange interaction. Therefore, we can increase the current density or higher optical confinement to verify the MEL line-shape changing phenomena. Furthermore, we use another light-emitting polymer to verify the phenomena can be repeated in different kind of material.

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