以分子束磊晶術成長硒化錳鎘磊晶層的光學特性研究

Optical Properties of Cd1-xMnxSe Epilayers Grown by Molecular Beam Epitaxy

謝思瑜(Ssu-Yu Hsieh)

指導教授 ： 邱寬城 ； 周武清

中原大學/理學院/應用物理研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500373

摘要

使用分子束磊晶法於砷化鎵（001）基板上，以硒化鋅磊晶層作為緩衝層，成長不同濃度的硒化錳鎘磊晶層。硒化錳鎘磊晶層中晶格常數與錳濃度呈現線性關係，並以光激螢光與反射光譜量測硒化錳鎘磊晶層能隙隨錳的濃度增加而變大。由變化溫度的光激螢光光譜，可知能量隨著溫度增加產生紅位移，光激螢光線寬也變寬。由變溫光激螢光光譜的Arrhenius圖，求熱抑制光激螢光強度活化能，發現隨錳濃度的增加而增加。此外，使用瓦希尼（Varshni）關係式來模擬實驗中能隙與溫度的變化。
另外也利用光譜來研究基板傾斜角度對硒化錳鎘磊晶層的能隙的影響。硒化錳鎘磊晶層能隙隨著傾斜角度而增加，在傾斜基板上成長硒化錳鎘磊晶層與能隙的關係幾乎是線性的，在小的傾斜角度下成長，所能影響的能隙隨之減小，相對於傾斜角度大於10度，對硒化錳鎘磊晶層能隙影響劇增。

關鍵字

硒化錳鎘

並列摘要

Cd1-xMnxSe epilayers were grown on GaAs (001) substrates with ZnSe buffer layer by molecular beam epitaxy for Mn composition from x=0 to 0.44. The lattice constants of the Cd1-xMnxSe epilayers were found to vary linearly with Mn composition. The optical properties of the epilayers were investigated by using photoluminescence (PL) and reflectivity measurements. The energy gap of the epilayers increases linearly with Mn composition. Temperature-dependent PL measurement shows a red shift in the peak energy and a linear increasing of the emission line width with temperature. The increase in the exciton activation energies for thermal quenching the PL intensity increases with the increasing Mn composition. Furthermore, the Varshni’s relation, which mimics the temperature dependence of energy gaps, was used to fit the experimental data.
The effect of substrate mis-orientation angle (SMA) on the band gap energies of II-VI compound semiconductor epilayers, Cd1-xMnxSe, was also studied by optical spectroscopy. The band gap energies were found to increase with substrate mis-orientation (tilted) angle. The dependence of the energy gap on SMA shows an initial decrease at low SMA then an abrupt increase at SMA=10 degrees.

並列關鍵字

CdMnSe

參考文獻

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