Optoelectronically Active GaAs/GeSn‐MQW/Ge Heterojunctions Created via Semiconductor Grafting
ABSTRACT Semiconductor devices have traditionally relied on lattice‐matched heterojunctions formed via epitaxy. However, expanding device functionalities increasingly demands integration across extreme lattice mismatches. Here, a lattice‐mismatched, single‐crystalline GaAs/GeSn‐multi‐quantum well (MQW)/Ge n‐i‐p heterojunction photodiode is realized through advanced “semiconductor grafting” technology. This method enables simultaneous engineering of band alignment and optical field distribution. Comprehensive STEM characterization reveals an atomically clean GaAs/GeSn‐MQW interface with no observable interdiffusion. The resulting photodiode exhibits outstanding performance: a record‐low dark current density of 1.22 × 10 −7 A/cm 2 , extended spectral response from ∼0.5 to 2 µm, and high photo responsivities of 0.85 A/W and 0.40 A/W at 520 nm (VIS) and 1570 nm (NIR), respectively. Compared to epitaxial reference device, this represents a reduction in dark current by over five orders of magnitude, and responsivity enhancements of ∼7× in the VIS and ∼3× in the NIR ranges. This work establishes a new strategy for constructing lattice‐mismatched optoelectronic heterojunctions. Beyond the GaAs/GeSn‐MQW/Ge system, the approach offers a broadly applicable platform for high‐performance device integration free from conventional strict lattice‐matching requirement.
Authors
- Jiarui Gong (ORCID: https://orcid.org/0000-0002-7304-4763)
- Munho Kim (ORCID: https://orcid.org/0000-0002-0379-1886)
- Xiao Gong (ORCID: https://orcid.org/0000-0002-9243-1937)
- Alireza Abrand (ORCID: https://orcid.org/0000-0003-0912-1979)
- Yi Lu (ORCID: https://orcid.org/0000-0002-4034-5869)
- Shui-Qing Yu (ORCID: https://orcid.org/0000-0002-4439-3729)
- Parsian K. Mohseni (ORCID: https://orcid.org/0000-0002-9377-7454)
- Kai Sun (ORCID: https://orcid.org/0000-0003-1745-9136)
- Mikhail A. Kats (ORCID: https://orcid.org/0000-0003-4897-4720)
- Guo‐En Chang (ORCID: https://orcid.org/0000-0002-3739-5451)
- Zetian Mi (ORCID: https://orcid.org/0000-0001-9494-7390)
- Yiran Li (ORCID: https://orcid.org/0000-0003-4285-2079)
- Jianping Shen (ORCID: https://orcid.org/0000-0002-7669-6046)
- Jie Zhou (ORCID: https://orcid.org/0000-0001-5730-4521)
- Shengqiang Xu
- Daniel Vincent (ORCID: https://orcid.org/0000-0002-4845-0604)
- Samuel Haessly (ORCID: https://orcid.org/0000-0002-2840-5427)
- Zhenqiang Ma
- Po Rei Huang
- Yifu Guo
- Haibo Wang (ORCID: https://orcid.org/0009-0008-9349-3612)
- Yang Liu (ORCID: https://orcid.org/0000-0002-1053-8205)
Institutions
- University of Wisconsin–Madison (US)
- National Chung Cheng University (TW)
- Rochester Institute of Technology (US)
- The University of Texas at Dallas (US)
- National University of Singapore (SG)
- Nanyang Technological University (SG)
- University of Michigan (US)
- University of Arkansas at Fayetteville (US)
Publication Details
- Journal
- Advanced Optical Materials
- Published
- 2026-04-25
- DOI
- https://doi.org/10.1002/adom.202502543
- Primary Topic
- Photonic and Optical Devices
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Air Force Office of Scientific Research