中国物理B ›› 2026, Vol. 35 ›› Issue (6): 67303-067303.doi: 10.1088/1674-1056/ae53b7

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Strain-enhanced optical gain of hexagonal Ge nanowire

Xue-Li Zhao(赵雪丽)1,2, Shan Guan(管闪)1,2,†, Zhigang Song(宋志刚)3,2, and Jun-Wei Luo(骆军委)1,2,‡   

  1. 1 State Key Laboratory of Semiconductor Chip Physics and Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;
    2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Laboratory of Solid-State Optoelectronics Information Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • 收稿日期:2026-01-28 修回日期:2026-03-04 接受日期:2026-03-18 出版日期:2026-05-28 发布日期:2026-05-28
  • 通讯作者: Shan Guan, Jun-Wei Luo E-mail:shan_guan@semi.ac.cn;jwluo@semi.ac.cn
  • 基金资助:
    The work is supported by the National Key R&D Program of China (Grant No. 2024YFA1408200), the National Natural Science Foundation of China (Grant Nos. 12525402 and 12374078), and the CAS Project for Young Scientists in Basic Research (Grant Nos. YSBR-120 and YSBR-026).

Strain-enhanced optical gain of hexagonal Ge nanowire

Xue-Li Zhao(赵雪丽)1,2, Shan Guan(管闪)1,2,†, Zhigang Song(宋志刚)3,2, and Jun-Wei Luo(骆军委)1,2,‡   

  1. 1 State Key Laboratory of Semiconductor Chip Physics and Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;
    2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
    3 Laboratory of Solid-State Optoelectronics Information Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
  • Received:2026-01-28 Revised:2026-03-04 Accepted:2026-03-18 Online:2026-05-28 Published:2026-05-28
  • Contact: Shan Guan, Jun-Wei Luo E-mail:shan_guan@semi.ac.cn;jwluo@semi.ac.cn
  • Supported by:
    The work is supported by the National Key R&D Program of China (Grant No. 2024YFA1408200), the National Natural Science Foundation of China (Grant Nos. 12525402 and 12374078), and the CAS Project for Young Scientists in Basic Research (Grant Nos. YSBR-120 and YSBR-026).

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摘要： The absence of an efficient light source compatible with silicon complementary metal-oxide-semiconductor technology remains a pivotal bottleneck in integrated photonics. Recently, the hexagonal diamond phase of germanium (2H-Ge) has emerged as a promising alternative in light of the direct nature of its bandgap, yet its light emission efficiency falls behind that of III-V semiconductors. Here, by performing theoretical calculations using an atomistic semi-empirical pseudopotential method, we systematically investigate the electronic structure and interband optical gain of [0001]-oriented 2H-Ge nanowires (NWs). We show that quantum confinement in pure 2H-Ge NWs enables diameter-tunable bandgaps across the infrared spectrum, but retains a pseudodirect character with weak near-band-edge optical transitions at the Brillouin zone center. Interestingly, we demonstrate that a moderate uniaxial tensile strain can induce a conduction band inversion, which dramatically enhances the optical gain by over two orders of magnitude and switches the dominant polarization of the emission. We illustrate such an enhancement by correlating the gain characteristics with the energy ordering of the active conduction band states. Our results thus provide essential theoretical guidance and optimization strategies to realize high-performance, polarized light emitters based on 2H-Ge NWs for integrated photonic applications.

关键词: hexagonal germanium nanowires, uniaxial strain, optical gain, electronic properties

Abstract: The absence of an efficient light source compatible with silicon complementary metal-oxide-semiconductor technology remains a pivotal bottleneck in integrated photonics. Recently, the hexagonal diamond phase of germanium (2H-Ge) has emerged as a promising alternative in light of the direct nature of its bandgap, yet its light emission efficiency falls behind that of III-V semiconductors. Here, by performing theoretical calculations using an atomistic semi-empirical pseudopotential method, we systematically investigate the electronic structure and interband optical gain of [0001]-oriented 2H-Ge nanowires (NWs). We show that quantum confinement in pure 2H-Ge NWs enables diameter-tunable bandgaps across the infrared spectrum, but retains a pseudodirect character with weak near-band-edge optical transitions at the Brillouin zone center. Interestingly, we demonstrate that a moderate uniaxial tensile strain can induce a conduction band inversion, which dramatically enhances the optical gain by over two orders of magnitude and switches the dominant polarization of the emission. We illustrate such an enhancement by correlating the gain characteristics with the energy ordering of the active conduction band states. Our results thus provide essential theoretical guidance and optimization strategies to realize high-performance, polarized light emitters based on 2H-Ge NWs for integrated photonic applications.

Key words: hexagonal germanium nanowires, uniaxial strain, optical gain, electronic properties

中图分类号:  (Quantum wires)

  • 73.21.Hb
42.50.Wk (Mechanical effects of light on material media, microstructures and particles) 42.60.Lh (Efficiency, stability, gain, and other operational parameters) 73.22.-f (Electronic structure of nanoscale materials and related systems)