| Citation: |
Sun Yongwei, Ma Wenquan, Yang Xiaojie, Qu Yuhua, Hou Shihua, Jiang Desheng, Sun Baoquan, Chen Lianghui. Infrared Absorption of Spatially Ordered Quantum Dot Superlattices[J]. Journal of Semiconductors, 2005, 26(11): 2092-2096.
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Sun Y W, Ma W Q, Yang X J, Qu Y H, Hou S H, Jiang D S, Sun B Q, Chen L H. Infrared Absorption of Spatially Ordered Quantum Dot Superlattices[J]. Chin. J. Semicond., 2005, 26(11): 2092.
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Infrared Absorption of Spatially Ordered Quantum Dot Superlattices
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Abstract
A self-organized InGaAs/GaAs quantum dot superlattice structure with three dimensionally spatial ordering is grown at 540℃ by molecular beam epitaxy.A Fourier transform infrared (FTIR) spectroscopy measurement demonstrates a distinct intersubband transition absorption peak with the wavelength centered at 11μm under the normal incidence geometry.As a comparison,the FTIR measurement shows that the same structure grown at 480℃ does not have normal incidence intersubband transition absorption.High resolution X-ray diffraction measurements indicate that the quantum dot superlattice grown at high temperatures has a better crystalline quality than that grown at low temperatures.Atomic force microscopy measurements reveal that the quantum dots grown at 540℃ show clear lateral ordering,while those grown at 480℃ show a lack of lateral ordering.In order to remove the interference effect under the normal incidence geometry,the normal incidence absorption measurement is proposed, using the structure with the same growth condition but without doping the quantum dot layers.The accuracy and the resolution of the measurement under normal incidence geometry are therefore enhanced.Our results indicate that the quantum dot superlattice structure with spatial ordering is more suitable to be utilized in the infrared photodetector than the structure without spatial ordering. -
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