摘要
Quantum well intermixing techniques modify the geometric shape of quantum wells to allow postgrowth adjustments.The tuning effect on the optical response property of a GaAs/AlGaAs quantum well infrared photodetector(QWIP) induced by the interdifussion of Al atoms was studied theoretically.By assuming an improvement of the heterointerface quality and an enhanced Al interdiffusion caused by postgrowth intermixings,the photoluminescence spectrum shows a blue-shifted,narrower and enhanced photoluminescence peak.The infrared optical absorption spectrum also shows the expected redshift of the response wavelength.However,the variation in the absorption peak intensity depends on the boundary conditions of the photo generated carriers.For high-quality QWIP samples,the mean free path of photocarriers is long so that the photocarriers are largely coherent when they transport across quantum wells.In this case,the enhanced Al interdiffusion can significantly degrade the infrared absorption property of the QWIP.Special effects are therefore needed to maintain and/or improve the optical properties of the QWIP device during postgrowth treatments.
Quantum well intermixing techniques modify the geometric shape of quantum wells to allow postgrowth adjustments. The tuning effect on the optical response property of a GaAs/AlGaAs quantum well infrared photodetector (QWIP) induced by the interdifussion of Al atoms was studied theoretically. By assuming an improvement of the heterointerface quality and an enhanced Al interdiffusion caused by postgrowth intermixings, the photoluminescence spectrum shows a blueshifted, narrower and enhanced photoluminescence peak. The infrared optical absorption spectrum also shows the expected redshift of the response wavelength. However, the variation in the absorption peak intensity depends on the boundary conditions of the photo generated carriers. For high-quality QWIP samples, the mean free path of photocarriers is long so that the photocarriers are largely coherent when they transport across quantum wells. In this case, the enhanced Al interdiffusion can significantly degrade the infrared absorption property of the QWIP. Special effects are therefore needed to maintain and/ or improve the optical properties of the QWIP device during postgrowth treatments.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第1期1-5,共5页
Journal of Infrared and Millimeter Waves
基金
TheprojectispartiallysupportedbytheNationalNaturalScienceFoundationofChina(10474020)
关键词
吸收光谱
量子阱
红外光电探测器
修正
quantum well infrared detector(QWIP)
quantum well intermixing (QWI)
boundary condition
optical absorption spectrum