氮化砷銦鎵單層量子井與 砷化銦量子點的光學特性研究

Optical properties of InGaAsN/GaAs single quantum wells and InAs/GaAs quantum dot

江佳諭(Chia-Ya Chiang)

指導教授 ： 沈志霖

中原大學/理學院/應用物理研究所/碩士(2008年)

https://doi.org/10.6840/cycu200800449

摘要

摘要
本文利用光激螢光光譜與時間鑑別光激螢光光譜來研究氮化銦砷鎵單層量子井與砷化銦量子點塗佈奈米金團簇的光學特性研究。於氮化銦砷鎵單層量子井變溫光激螢光光譜中，發現隨溫度增加其能量峰值有下降、上升、再下降的現象。此S-型行為是因載子受到熱能的活化，脫離侷限躍遷而產生的。由S-型行為擬合實驗所求的侷限深度，與利用變溫下螢光強度所得的活化能以及低溫下侷限深度相吻合（侷限深度約為12 meV）。此外，根據變溫下載子生命期的變化，也與S-型行為相吻合。
利用奈米金團簇塗佈於砷化銦量子點的表面上，因奈米金團簇粒子提升吸收與散射效率，導致光激螢光的強度上升。並發現越多層量子點時其螢光強度增強越多。此外，其載子生命期也因塗佈奈米金團簇增加。

關鍵字

奈米金團簇 ； 砷化銦 ； S-型 ； 氮化銦砷鎵

並列摘要

Abstract
We investigated optical properties of the InGaAsN/GaAs single quantum wells and the InAs/GaAs quantum dots incorporated with nanogold clusters by using photoluminescence (PL) and time-resolved photoluminescence(TRPL). Base on the temperature dependence of PL spectra in the InGaAsN/GaAs quantum wells, we observed that the PL peak energy shifts toward the lower energy, the higher energy, and the lower energy with increasing temperature (the S-shaped behavior). About This S-shaped behavior, we suggest that the localized carrier can be delocalized by thermalization. The localized depth (about 12 meV) fitted by the S-shaped behavior is in good agreement with the activation energy obtained from temperature-dependent PL intensity. In addition, the S-shaped behavior can be explained by evolution of the carrier lifetime with increasing temperature.
Introducing the nanogold clusters on surface of the InAs/GaAs quantum dots was also investigated. It was found the PL intensity of the InAs/GaAs quantum dots is enhanced after incorporation of the nanogold clusters. The enhancement effect increases as the number of the quantum- dot layers increases. Moreover, the carrier lifetime increases after introduction of the nanogold clusters on the surface of the InAs/GaAs quantum dots. The enhancement of the absorption and scattering are suggested to be responsible for the enhancement of PL in quantum dots.

並列關鍵字

nanogold clusters ； InAs ； S-shaped ； InGaAsN

參考文獻

[5] Fang-I. Lai, S.Y. Kuo, J.S. Wang, R.S. Hsiao, H.C. Kuo, J. Chi, S.C. Wang, H.S. Wang, C.T. Liang, Y.F. Chen, Journal of Crystal Growth 291, 27 (2006)

[6] M.-A. Pinault and E. Tourni, Appl. Phys. Lett. 78, 1562 (2001)

[8] Fang-I Lai, S. Y. Kuo, J. S. Wang, H. C. Kuo, S. C. Wang. H. S. Wang, C. T. Liang, and Y. F. Chen, J. Vac. Sci. Technol. A, 24, 1223 (2006)

[10] A. Mooradian, Phys. Rev. Lett. 22, 185 (1969)

[12] T. Huang and R. W. Murray, J. Phys. Chem. B, 105, 12498 (2001)