以分子束磊晶法成長硒化鎘量子點/硒化鋅/硒化鋅鎘錳量子井耦合結構及其光激螢光特性分析

Growth and characteristics of photoluminescence of coupled CdSe quantum dots/ZnSe/ZnCdMnSe quantum wells grown by molecular beam epitaxy

陳與偉(YU-WEI CHEN)

指導教授 ： 王智祥

中原大學/理學院/物理研究所/碩士(2012年)

https://doi.org/10.6840/cycu201200049

摘要

本文研究硒化鎘量子點與硒化鋅鎘錳量子井間的耦合效應。並利用原子力顯微鏡與光激螢光光譜等實驗技術來探究其表面形貌與螢光特性。我們發現在不平坦硒化鋅緩衝層上成長硒化鋅鎘錳量子井，會因為介面處的不平整導致成長硒化鋅鎘錳量子井時形成相分離。我們在有覆蓋層的樣品光激螢光中可清楚區分三處螢光訊號，其中一處的訊號為硒化鎘量子點，另外兩處的訊號為硒化鋅鎘錳量子井因相分離所產生的螢光。我們研究不同中間層厚度對硒化鎘量子點與硒化鋅鎘錳量子井間偶合效應的影響。結果顯示，當硒化鋅中間層厚度低於20 nm時，耦合效應會隨著硒化鋅中間層厚度減少而提高，相對於光激螢光光譜可看到硒化鋅鎘錳量子井訊號強度的減少。這是載子穿隧導致的耦合結果。

關鍵字

分子束磊晶法 ； 硒化鋅鎘錳

並列摘要

The coupled structures of self-assembled CdSe quantum dots (QDs) separated by a thin ZnSe barrier from a ZnCdMnSe quantum wells (QWs) were studied. Atomic force microscopy (AFM) and photoluminescence (PL) were employed to investigate the surface morphology and the optical properties respectively. A PL peak originated from the CdSe QDs and two PL peaks originated from the phase-separated ZnCdMnSe QWs were observed. Furthermore, we investigated the effect of thickness of ZnSe spacer on the coupling of the CdSe QDs and the ZnCdMnSe QWs. As the thickness of ZnSe spacer layer was less than 20 nm, the PL intensity originated from the QWs decreased with the thickness of spacer layer decreased. The results consist with the tunneling effect of carriers in the coupled structures.

並列關鍵字

molecular beam epitaxy ； ZnCdMnSe

參考文獻

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