High-Performance Flexible InAs Thin-Film Photodetector Arrays with Heteroepitaxial Growth Using an Abruptly Graded in xAl1- xAs Buffer

Seungwan Woo, Geunhwan Ryu, Soo Seok Kang, Tae Soo Kim, Namgi Hong, Jae Hoon Han, Rafael Jumar Chu, In Hwan Lee, Daehwan Jung, Won Jun Choi

Research output: Contribution to journalArticlepeer-review

Abstract

Current infrared thermal image sensors are mainly based on planar firm substrates, but the rigid form factor appears to restrain the versatility of their applications. For wearable health monitoring and implanted biomedical sensing, transfer of active device layers onto a flexible substrate is required while controlling the high-quality crystalline interface. Here, we demonstrate high-detectivity flexible InAs thin-film mid-infrared photodetector arrays through high-yield wafer bonding and a heteroepitaxial lift-off process. An abruptly graded InxAl1-xAs (0.5 < x < 1) buffer was found to drastically improve the lift-off interface morphology and reduce the threading dislocation density twice, compared to the conventional linear grading method. Also, our flexible InAs photodetectors showed excellent optical performance with high mechanical robustness, a peak room-temperature specific detectivity of 1.21 × 109 cm-Hz1/2/W at 3.4 μm, and excellent device reliability. This flexible InAs photodetector enabled by the heteroepitaxial lift-off method shows promise for next-generation thermal image sensors.

Original languageEnglish
Pages (from-to)55648-55655
Number of pages8
JournalACS Applied Materials and Interfaces
Volume13
Issue number46
DOIs
Publication statusPublished - 2021 Nov 24

Keywords

  • epitaxial lift-off
  • heteroepitaxial growth
  • metal wafer bonding
  • mid-infrared
  • molecular beam epitaxy
  • photodetector

ASJC Scopus subject areas

  • Materials Science(all)

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