Flexible GaAs Photodetectors with Ultrathin Thermally Grown Silicon Dioxide as a Long‐Lived Barrier for Chronic Biomedical Implants. Issue 2 (17th December 2020)

• Record Type: Journal Article
• Authors: Hong, Namgi; Geum, Dae-Myeong; Kim, Tae Soo; Ahn, Seung-yeop; Han, Jae-Hoon; Jung, Daehwan; Ryu, Geunhwan; Kim, SangHyeon; Yu, Ki Jun; Choi, Won Jun
• Is Part Of: Advanced photonics research. Volume 2:Issue 2(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-17
• Subjects: epitaxial lift-offs -- flexible photodetectors -- implantable devices -- metal wafer bondings -- thermal silicon dioxide; Photonics -- Periodicals; 621.36505
• DOI: 10.1002/adpr.202000051
• Languages: English
• ISSNs: 2699-9293

Abstract

Abstract : Herein, an approach to form high‐quality GaAs‐based flexible photodetectors (PDs) is first demonstrated by metal wafer bonding (MWB) and high‐throughput epitaxial lift‐off (ELO) with encapsulated thermally grown silicon dioxide (t‐SiO2 ) for chronic biomedical implants. The flexible GaAs PDs demonstrate responsivity over a wide range of visible and near‐infrared wavelengths. Regarding certain diagnoses, high‐performance PDs are essential for precise treatments with long‐term optoelectronic implants, and the long‐term stability and reliable encapsulation of GaAs PDs will play a major role when optoelectronics are injected into biofluids. t‐SiO2, as an encapsulation barrier, is stable without increasing the leakage current for over 120 h in phosphate‐buffered saline (PBS) at 70 °C. By Arrhenius scaling, the device shows a 700‐day lifetime with stable operation in a biofluid at 37 °C. Finally, by measuring the mass of arsenic using an inductively coupled plasma mass spectrometer (ICP/MS), the t‐SiO2 encapsulation barrier is capable of preventing toxic elements from leaching out to surrounding tissues. The technology may provide approaches based on III–V materials for expanding high‐performance optoelectronic devices to biomedical implants, namely, a broad range of high‐resolution retinal prostheses for blindness or the integration for measuring physiological parameters, such as tissue oxygenation and neural activity in the cerebral cortex. Abstract : The GaAs‐based flexible photodetector detects photoresponses from visible to near infrared wavelengths. Furthermore, the encapsulated t‐SiO2 III–V optoelectronic device exhibits long‐term electrical stability under a harsh environment (i.e., in vitro soaking test with phosphate buffer saline at 70 °C for 120 h) so that it can be utilized as a chronic‐stable electronics for biomedical implant applications.