Migration-Enhanced Epitaxial Growth of InAs/GaAs Short-Period Superlattices for THz Generation
Migration-Enhanced Epitaxial Growth of InAs/GaAs Short-Period Superlattices for THz Generation
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DOI：
10.3390/nano14030294
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发表时间：
2024-01
期刊：
影响因子：
5.3
通讯作者：
Ruolin Chen;Xuefei Li;Hao Du;Jianfeng Yan;Chongtao Kong;Guipeng Liu;Guangjun Lu;Xin Zhang;Shuxiang Song;Xinhui Zhang;Linsheng Liu
中科院分区：
文献类型：
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作者：
Ruolin Chen;Xuefei Li;Hao Du;Jianfeng Yan;Chongtao Kong;Guipeng Liu;Guangjun Lu;Xin Zhang;Shuxiang Song;Xinhui Zhang;Linsheng Liu
低温生长InGaAs （LT-InGaAs）光导天线因其高度紧凑和集成化的廉价太赫兹源而受到广泛关注。然而，LT-InGaAs光导天线的性能受到其低电阻率和迁移率的限制。与低温生长的gaas光导天线相比，产生的辐射功率要弱得多。这主要是由于传统生长方式下的LT-InGaAs中过量As丰度较低，退火后不可避免地会形成As析出物和合金散射。本文采用迁移增强分子束外延技术，在InP衬底上生长出具有尖锐界面的高质量（InAs）m/(GaAs)n短周期超晶格，取代了InGaAs。（InAs）m/(GaAs)n短周期超晶格的电子迁移率和室温电阻率（RT）分别为843 cm2/（V·s）和1648 ohm/sq。利用有限元法求解Maxwell波动方程和漂移-扩散/泊松耦合方程，计算得到光电流强度，与前人报道的结果吻合较好。本研究为高辐射功率高性能太赫兹光导天线的材料生长提供了新的途径。
The low-temperature-grown InGaAs (LT-InGaAs) photoconductive antenna has received great attention for the development of highly compact and integrated cheap THz sources. However, the performance of the LT-InGaAs photoconductive antenna is limited by its low resistivity and mobility. The generated radiated power is much weaker compared to the low-temperature-grown GaAs-based photoconductive antennas. This is mainly caused by the low abundance of excess As in LT-InGaAs with the conventional growth mode, which inevitably gives rise to the formation of As precipitate and alloy scattering after annealing. In this paper, the migration-enhanced molecular beam epitaxy technique is developed to grow high-quality (InAs)m/(GaAs)n short-period superlattices with a sharp interface instead of InGaAs on InP substrate. The improved electron mobility and resistivity at room temperature (RT) are found to be 843 cm2/(V·s) and 1648 ohm/sq, respectively, for the (InAs)m/(GaAs)n short-period superlattice. The band-edge photo-excited carrier lifetime is determined to be ~1.2 ps at RT. The calculated photocurrent intensity, obtained by solving the Maxwell wave equation and the coupled drift–diffusion/Poisson equation using the finite element method, is in good agreement with previously reported results. This work may provide a new approach for the material growth towards high-performance THz photoconductive antennas with high radiation power.