The electron mobility anisotropy in (Al,Ga)Sb/InAs two-dimensional electron gases with different surface morphology has been investigated.Large electron mobility anisotropy is found for the sample with anisotropic mor...The electron mobility anisotropy in (Al,Ga)Sb/InAs two-dimensional electron gases with different surface morphology has been investigated.Large electron mobility anisotropy is found for the sample with anisotropic morphology,which is mainly induced by the threading dislocations in the InAs layer.For the samples with isotropic morphology,the electron mobility is also anisotropic and could be attributed to the piezoelectric scattering.At low temperature (below transition temperature),the piezoelectric scattering is enhanced with the increase of temperature,leading to the increase of electron mobility anisotropy.At high temperature (above transition temperature),the phonon scattering becomes dominant.Because the phonon scattering is isotropic,the electron mobility anisotropy in all the samples would be reduced.Our results provide useful information for the comprehensive understanding of electron mobility anisotropy in the (Al,Ga)Sb/InAs system.展开更多
High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarif...High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.展开更多
基金Supported by the National Natural Science Foundation of China(61534006,61974152,61505237,61505235,61404148,61176082)the National Key Research and Development Program of China(2016YFB0402403)the Youth Innovation Promotion Association,CAS(2016219)
基金supported by NSFC (Grants No. 11834013 and 12174383)support from the Youth Innovation Promotion Association, Chinese Academy of Sciences (No. 2021110)。
文摘The electron mobility anisotropy in (Al,Ga)Sb/InAs two-dimensional electron gases with different surface morphology has been investigated.Large electron mobility anisotropy is found for the sample with anisotropic morphology,which is mainly induced by the threading dislocations in the InAs layer.For the samples with isotropic morphology,the electron mobility is also anisotropic and could be attributed to the piezoelectric scattering.At low temperature (below transition temperature),the piezoelectric scattering is enhanced with the increase of temperature,leading to the increase of electron mobility anisotropy.At high temperature (above transition temperature),the phonon scattering becomes dominant.Because the phonon scattering is isotropic,the electron mobility anisotropy in all the samples would be reduced.Our results provide useful information for the comprehensive understanding of electron mobility anisotropy in the (Al,Ga)Sb/InAs system.
基金financially supported by the National Natural Science Foundation of China(Nos.62074018,62174015 and 62275032)the Developing Project of Science and Technology of Jilin Province(No.20210509061RQ)+3 种基金the Natural Science Foundation of Jilin Province(No.20210101473JC)National Key R&D Program of China(No.2021YFB3201901)The Natural Science Foundation of Chongqing China(No.cstc2021jcyjmsxmX1060)supported by R&D project of Collighter Co.,Ltd。
文摘High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic devices.Improving the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic ations.In this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates successfully.Superlattices grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'results.Moreover,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more obvious.In addition,the optical properties of superlattices grown on different substrates are discussed systematically.Because of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared emission.Finally,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.
