本論文主要利用無接點式電場調制反射(CER)光譜來研究分子束磊晶所成長多重量子井和非對稱耦合量子井結構。
從CER光譜中能在很廣泛的範圍顯現出這些結構可能的光學躍遷訊號；然後藉由一階導數的勞倫茲線型函數去擬合來獲得躍遷能隙。和光激發螢光光譜(PL)譜線比較後能確定來自相同的量子井結構中的基態(ground state)躍遷訊號。為了確認其餘的躍遷訊號，我們利用封包方程式(envelope function)去計算；利用線性內插法來獲得電子、重電洞、輕電洞的有效質量參數，然後將導電帶能隙補償差(conduction-band band offset)視為可調變參數ΔEc = (0.75  0.05) ΔEg。所計算出來的值和實驗結果相當吻合。可利用傅里葉變換紅外光譜(Fourier transform infrared)來估算和驗證子能帶間的躍遷訊號。從實驗結果可得知CER是個非接觸、非破壞性的量測技巧，相當適合用於量測製作中紅外線區雷射元件的寬能隙II-VI族材料

Contactless electroreflectance (CER) was used to characterize the possible optical transitions in a Zn0.46Cd0.54Se/Zn0.24Cd0.25Mg0.51Se multiple quantum well (MQW) and a Zn0.48Cd0.52Se/Zn0.24Cd0.18Mg0.58Se asymmetric coupled quantum well (ACQW) structures grown on (001) semi-insulating InP by molecular beam epitaxy for midinfrared device applications.
The CER spectra revealed a wide range of the possible optical transition in the QW structures. The transition energies were obtained using a fitting process based on the first derivative of a Lorentzian lineshape. The ground state transitions were assigned by comparing with the PL emission signals taken from the same structures. In order to assign the remaining transitions, calculations were performed based on the envelope function approximation, considering that the well was doped. The values for the effective masses were obtained from a linear interpolation of the binary compounds. A value for the conduction-band band offset of ΔEc = 0.75  0.05 ΔEg was used. The identified transitions corresponded to the symmetry allowed and symmetry forbidden but parity allowed transitions. The calculation matched with the measured values. From these data, the intersubband transitions could be estimated and were further confirmed by Fourier transform infrared absorption measurements. The results demonstrate the potential of using CER as a technique for the contactless and nondestructive characterization of the wide band gap II-VI QW structures for mid-IR intersubband device applications.

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