利用分子束磊晶系統成長型態Ⅱ銻化鎵/砷化鎵量子環及其在元件上的應用

本論文主要是探討型態二砷化銻/砷化鎵量子環的表面形貌、發光特性及相關的元件應用。藉由在執行成長後銻原子浸潤時 (Sb post soaking) 時改變銻與背景砷原子的比例，我們可控制量子點或是量子環的的形成。相較於量子點結構，量子環較強的螢光放光強度是由於擁有較大的電子電洞波函數覆蓋及較多圍繞在量子環的周遭的電子數目。為了要更進一步的強化型態二量子環的螢光強度、我們提出具有較薄的砷化鎵隔離層的耦合量子環概念。當隔離層降低到五奈米時、耦合量子環結構呈現了更強的光激發光強度與較大的峰值能量藍位移，其原因是在於此結構改善了電子的侷限效果進而使得較多的電子累積在薄砷化鎵隔離層中。若再更進一步的降低隔離層的厚度到兩奈米時，樣品的螢光強度甚至超過了單層的型態一砷化銦/砷化鎵量子點樣品。類似於耦合量子環的概念，砷化銦鎵覆蓋的量子環提供了額外的電子侷限來提升螢光的發光強度。利用砷含量含有 15 % 的砷化銦鎵覆蓋層的量子環所做出來的發光二極體，我們製造出可調製波長從 1332 到 1252 奈米的發光二極體，此結果也證實室溫 1.3 微米電激發螢光可以很輕易藉由插入砷化銦鎵層覆蓋的銻化鎵量子環來達到，此結果對於銻化鎵量子環結構的實際應用有很大的幫助。

關鍵字

分子束磊晶；型態二；銻化鎵；量子環；發光二極體

並列摘要

In this thesis, the surface morphologies and optical characteristics of type-II GaSb quantum ring (QR) structures and its related device applications are investigated. By changing Sb/background As flux ratios during the post-growth Sb soaking procedure, either fully quantum-dot (QD) or QR morphologies can be obtained. The intense luminescence of GaSb QR structures is observed due to the increasing electron-hole wave function overlapping and more surrounding electron shells over the QRs. To further improve the luminescence intensities of the type-II QRs, coupled QRs separated by thin GaAs spacer layers are proposed. With 5 nm GaAs spacer layers, both stronger photoluminescence (PL) intensity and larger PL blue shift are observed, which are attributed to the larger number of electrons accumulated in the thin GaAs spacer layer resulted from improved electron confinement. With further reducing the GaAs spacer layer to 2 nm, the PL intensity of the sample is even more intense than a single-period type-I InAs quantum dots (QDs). Similar with coupled QRs, InGaAs-capped QR structures have provided additional electron confinement to enhance the luminescence intensity. By using In0.15Ga0.85As capped QRs embedded in GaAs PIN diode, a wavelength-tunable light-emitting device from 1332 to 1252 nm is fabricated, which demonstrates room-temperature 1.3 u electroluminescence can be easily achieved by using the type-II InGaAs-capped GaSb QR structure.

並列關鍵字

Molecular Beam Epitaxy ； Type-II ； GaSb ； Quantum Ring ； Light Eimitting Diode

參考文獻

[2] B. R. Bennett, R. Magno, and B. V. Shanabrook, “Molecular beam epitaxial growth of InSb, GaSb, and AlSb nanometer‐scale dots on GaAs”, Appl. Phys. Lett., vol. 68, pp. 505-507, November 1995.

[3] E. R. Glaser, B. R. Bennett, B. V. Shanabrook, and R. Magno, “Photoluminescence studies of self‐assembled InSb, GaSb, and AlSb quantum dot heterostructures”, Appl. Phys. Lett., vol. 68, pp. 3614-3616, April 1996.

[4] A Subekti, Melissa J Paterson, E.M Goldys, T.L Tansley, ” The influence of substrate on the self-organised island nucleation and morphology of metalorganic chemical vapour deposited GaSb”, Applied Surface Science, vol. 140, pp. 190-196, February 1999.

[5] Motlan and E. M. Goldys, “Photoluminescence of multilayer GaSb/GaAs self-assembled quantum dots grown by metalorganic chemical vapor deposition at atmospheric pressure”, Appl. Phys. Lett., vol. 79, pp. 2976-2978, August 2001.

[6] C.‐K. Sun, G. Wang, J. E. Bowers, B. Brar, H.‐R. Blank, H. Kroemer, and M. H. Pilkuhn, “Optical investigations of the dynamic behavior of GaSb/GaAs quantum dots”, Appl. Phys. Lett., vol. 68, pp. 1543-1545, January 1996.

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利用分子束磊晶系統成長型態Ⅱ銻化鎵/砷化鎵量子環及其在元件上的應用

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