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1. 宁波工程学院 机械学院,浙江 宁波,315016
2. 中国科学院 长春光学与精密机械研究所 激发态物理重点实验室,吉林 长春,130033
[ "ZHENG Jin-ju, born in 1980, female, Zhejiang Province. Her work focuses on synthesis of luminescent nanomaterials and their optoelectronic devices. E-mail: shudezjj@sohu.com, Tel: (0574)87080966 *: Corresponding Author" ]
[ "E-mail: zhengzhao2007@yahoo.cn" ]
收稿日期:2010-06-28,
修回日期:2010-08-15,
网络出版日期:2010-11-22,
纸质出版日期:2010-11-22
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郑金桔, 郑著宏. CdSe/ZnSe自组装量子点中非线性系数随着温度的规律性变化[J]. 发光学报, 2010,31(6): 836-841
ZHENG Jin-ju, ZHENG Zhu-hong. An Inerratic Variation of Nonlinear Coefficient with Temperature in CdSe/ZnSe Self-assembled Quantum Dots[J]. Chinese Journal of Luminescence, 2010,31(6): 836-841
研究了在CdSe/ZnSe自组装量子点中CdSe量子点的发光随着激发光强度变化的特性。发现当激发强度(
I
)变化3个数量级的时候
量子点发光的峰位、峰形都没有发生明显的变化。通过公式
L
I
k
(其中
I
是激发光强度
L
是量子点发光强度
k
是非线性系数)得到非线性系数k值。实验结果表明:在温度由21K升高到300K的过程中
k
值随温度变化可以分为3个区域:当温度低于120K时
k
值接近于1;然后
随着温度升高
k
值慢慢变小;最后
随温度进一步升高
k
值由200K时的0.946迅速减少到0.870。结合发光随温度变化的实验结果
确认在120K以下发光主要来源于束缚激子复合。在温度由200K升高到300K的过程中
非线性系数的单调减小主要归因于随着温度的升高
发光部分来自于由自由电子或空穴到束缚态能级(FB)的复合。进一步通过分析量子点发光的积分强度随着温度的变化的实验结果
发现发光强度随温度升高而减弱的主要原因是材料中的缺陷或者位错等提供非辐射渠道。
We have investigated the excitation-intensity-dependent optical properties of CdSe/ZnSe self-assembled quantum dots (QDs) at different temperature. When excitation intensity (
I
) is varied by three orders of magnitude
the photoluminescence (PL) morphology and peak positions appear to be independent on excitation intensity.The nonlinear coefficient
k
obtained by a relation of
LI
k
in the temperature ranges of 21~300 K shows regularity which is described in three temperature regions:
k
is close to 1
when the temperature is below 120 K
it slightly decreases with increasing temperature in ranges of 120~200 K and it rapidly decreases from 0.946 to 0.870 with the temperature in the ranges of 200~300 K. Taking the temperature dependence of PL into account
we have confirmed that the bound excitonic recombination is a dominant recombination mechanism below 120 K. The nonlinear coefficient
k
monotonously decreases in the temperature ranges of 120~300 K
which is attributed to increasing transition from free-to-bound (FB) exciton with increasing temperature. Furthermore
the temperature dependence of integrated PL intensity reveals that defects and dislocations in the material provide nonradiative channels to quench the luminescence.
Ko H C, Park D C, Kawakami K, et al. Self-organized CdSe quantum dots onto cleaved GaAs (110) originating from Stranski-Krastanow growth mode [J]. Appl. Phys. Lett., 1997, 70 (24):3278-3280.[2] Zheng J J, Zheng Z H, Gong W W, et al. Abnormal temperature behavior of photoluminescence in CdSe/ZnSe self-assembled quantum dots [J]. Sol. Stat. Commun., 2008, 147 (11-12):429-432.[3] Zheng Z H, Okamoto K. Narrow luminescence lines from self-assembled CdSe quantum dots at room temperature [J]. Appl. Phys. Lett., 2001, 78 (3):297-299.[4] Stier O, Grundmann M, Bimberg D. Electronic and optical properties of strained quantum dots modeled by 8-band kp theory [J]. Phys. Rev. B, 1999, 59 (8):5688-5701.[5] Pryor C, Flatte M. Accuracy of circular polarization as a measure of spin polarization in quantum dot qubits [J]. Phys.Rev. Lett., 2003, 91 (25):257901-1-4.[6] Hogele A, Seidl S, Kroner M, et al. Voltage-controlled optics of a quantum dot [J]. Phys. Rev. Lett., 2004, 93 (21):217401-1-4.[7] Michler P. Single Quantum Dots: Fundamentals, Applications and New Concepts [M]. Berlin: Springer, 2003.[8] Tang S F, Chiang C D, Weng P K, et al. Interferometric analog-to-digital conversion scheme [J]. IEEE Photonics Tech-nol. Lett., 2006, 18 (8):986-988.[9] Regelman D V, Mizrahi U, Gershoni D, et al. Semiconductor quantum dot: A quantum light source of multicolor photons with tunable statistics [J]. Phys. Rev. Lett., 2001, 87 (25):257401-1-4.[10] Strauf S, Hennessy K, Rakher M T. Self-tuned quantum dot gain in photonic crystal lasers [J]. Phys. Rev. Lett., 2006, 96 (12):127404-1-4.[11] He J, Krenner H J, Pryor C, et al. Growth, structural, and optical properties of self-assembled (In,Ga)As quantum posts on GaAs [J]. Nano Lett., 2007, 7 (3):802-806.[12] Gao W, Zheng Z H, Zheng J J, et al. Photoluminescence of CdSe/ZnSe asymmetric quantum wells [J]. Chin. J. Lumin. (发光学报), 2007, 28 (6):907-912 (in Chinese).[13] Hu X B, Zheng Z H, Zheng J J, et al. Photoluminescence of self-assembled CdSe quantum dots with different thickness CdSe quantum well layers [J]. Chin. J. Lumin. (发光学报), 2008, 29 (5):724-728 (in Chinese).[14] Rosen D L, Li Q X, Alfano R R, et al. Native defects in undoped semi-insulating CdSe studied by photoluminescence and absorption [J]. Phys. Rev. B, 1985, 31 (4):R2396-R2403.[15] Furdyna J K, Lee S. Optical properties of self-assembled Ⅱ-Ⅵ quantum dots [J]. SPIE, 1998, 3283 :774-784.[16] Schmidt T, Lischka K. Excitation-power dependence of the near-band-edge photoluminescence of semiconductors [J]. Phys. Rev. B, 1992, 45 (16):R8989-8994.[17] Wachter S, Don D D, Schmidt M, et al. Relaxation of localized excitons in CdSe/ZnSe heterostructures containing quantum islands of different sizes [J]. Phys. Stat. Sol. (b), 2001, 224 (2):437-441.[18] Wang F Z, Chen Z H. The micro-photoluminescence and micro-Raman study of Zn1-xCdx Se quantum islands (dots) in CdSe/ZnSe heterostructure [J]. Acta Physica Sinica (物理学报), 2006, 55 (5):2628-2632 (in Chinese).[19] Karczewski G, Mackowski S, Kutrowski M, et al. Photoluminescence study of CdTe/ZnTe self-assembled quantum dots [J]. Appl. Phys. Lett., 1999, 74 (20):3011-3013.[20] Bauknecht A, Siebentritt S, Albert J. Radiative recombination via intrinsic defects in CuxGaySe2 [J]. J. Appl. Phys., 2001, 89 (8):4391-4440.[21] Schairer W, Schmidt M. Strongly quenched deformation potentials of the Mn acceptor in GaAs [J]. Phys. Rev. B, 1974, 10 (6):R2501-2506.[22] Mayer H, Rssler U, Wolf K, et al. Strain splitting of nitrogen acceptor levels in ZnSe [J]. Phys. Rev. B, 1995, 52 (7):4956-4964.
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