磁性半導體的磁性來源來自於磁性原子的直接交互作用，在稀磁性半導體中，磁性原子間的距離較遠，磁性難以來自於原子之間的直接交互作用，於是提出許多模型來解釋磁性的來源，主要的模型多數來自於載子做為媒介的交互作用，有雙交換交互作用(Double exchange)、RKKY 交互作用、束縛極化子模型(Bound Magnetic PolaronModel)，然而在氧化鋅摻鈷系統裡面，雙交換交互作用來自於不同價數的原子，電子
會在不同原子間交換，鈷原子跟鋅原子皆為二價陽離子，而RKKY 交互作用存在於高載子濃度系統的半導體當中，以載子做為磁性原子電子的媒介交換磁性原子的訊號，但即使是低載子的氧化鋅摻鈷系統，仍然可以量到鐵磁性，於是束縛極化子模型成為
主要的模型， 認為氧化鋅摻雜過渡金屬的鐵磁性來源，來自於磁性原子的3d 軌域電子跟氧空缺的impurity band 形成混成軌域，也就是氧空缺必須臨近過渡金屬原子，而束縛的電子會將磁性的訊號仍被侷限在一定範圍，本實驗室希望利用硬X-ray 光電子解析能譜儀(Hard X-ray Photoelectron Spectroscopy, HAXPES)直接量測氧化鋅摻鈷的電子結構，證明氧化鋅摻鈷的鐵磁性，來自於鈷磁性原子的3d 軌域電子跟氧空缺的impurity band 形成混成軌域，進而確立這個模型，並推廣到所有金屬氧化物摻雜過渡金屬，同時應用到發光二極體當中，藉由氧化鋅摻鈷薄膜具有磁性和良導電的特性，在不影響電壓的情況下，產生些微磁阻的效應和利用能隙間距不一致產生的位能井，使得注入作用區的電子數目減少，解決載子濃度不平衡和高載子濃度導致的內部量子效益下降問題。

A detailed understanding of the origin of the magnetism in dilute magnetic semiconductor is crucial to the application. We use pulsed laser deposition (PLD) and magnetron sputter to grow CoxZn1-xO thin film . Then, we investigate CoxZn1-xO thin film using hard X-ray angle-resolved photoemission (HARPES) with 6669 eV polarization light which can distinguish electrons come from the different orbit and extended X-ray absorption fine structure (EXAFS) to determine the local structure surrounding cobalt atoms. Using EXAFS to make sure the cobalt atoms are doped in the ZnO system. And then the measurement of the HARPES directly observing Co 3d↑-induced states in valence-band centred about 2.7eV below Fermi level and Co 3d↓-induced states near Fermi lever centred about 0.6eV below hybridizing with impurity band created by oxide vacancy. And confirm the ferromagnetism become stronger as the increasing oxide vacancy. We also use Co0.07Zn0.93O to insert into LED as a quantum wall. Solving the problem of the carrier concentration of n-GaN is larger than p-GaN. There is about 24.6% increasing efficiency after growing 20nm Co0.07Zn0.93O between n-GaN and electrode.

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