TY - JOUR
T1 - Ultraflexible near-infrared organic photodetectors for conformal photoplethysmogram sensors
AU - Park, Sungjun
AU - Fukuda, Kenjiro
AU - Wang, Ming
AU - Lee, Chulhyo
AU - Yokota, Tomoyuki
AU - Jin, Hanbit
AU - Jinno, Hiroaki
AU - Kimura, Hiroki
AU - Zalar, Peter
AU - Matsuhisa, Naoji
AU - Umezu, Shinjiro
AU - Bazan, Guillermo C.
AU - Someya, Takao
N1 - Funding Information:
This work was financially supported by the JST PRESTO (Grant number JPMJPR1428) and the JST ACCEL (Grunt Number JPMJMI17F1). The authors would like to thank Dr. K. Tajima and of CEMS, RIKEN, Japan for their technical support and helpful discussions.
Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2018/8
Y1 - 2018/8
N2 - Flexible organic optoelectronic devices simultaneously targeting mechanical conformability and fast responsivity in the near-infrared (IR) region are a prerequisite to expand the capabilities of practical optical science and engineering for on-skin optoelectronic applications. Here, an ultraflexible near-IR responsive skin-conformal photoplethysmogram sensor based on a bulk heterojunction photovoltaic active layer containing regioregular polyin-dacenodithiophene-pyridyl[2,1,3]thiadiazole-cyclopentadithiophene (PIPCP) is reported. The ultrathin (3 µm thick) photodetector exhibits unprecedented operational stability under severe mechanical deformation at a bending radius of less than 3 µm, even after more than 103 bending cycles. Deliberate optimization of the physical dimensions of the active layer used in the device enables precise on/off switching and high device yield simultaneously. The response frequency over 1 kHz under mechanically deformed conditions facilitates conformal electronic sensors at the machine/human interface. Finally, a mechanically stretchable, flexible, and skin-conformal photoplethysmogram (PPG) device with higher sensitivity than those of rigid devices is demonstrated, through conformal adherence to the flexuous surface of a fingerprint.
AB - Flexible organic optoelectronic devices simultaneously targeting mechanical conformability and fast responsivity in the near-infrared (IR) region are a prerequisite to expand the capabilities of practical optical science and engineering for on-skin optoelectronic applications. Here, an ultraflexible near-IR responsive skin-conformal photoplethysmogram sensor based on a bulk heterojunction photovoltaic active layer containing regioregular polyin-dacenodithiophene-pyridyl[2,1,3]thiadiazole-cyclopentadithiophene (PIPCP) is reported. The ultrathin (3 µm thick) photodetector exhibits unprecedented operational stability under severe mechanical deformation at a bending radius of less than 3 µm, even after more than 103 bending cycles. Deliberate optimization of the physical dimensions of the active layer used in the device enables precise on/off switching and high device yield simultaneously. The response frequency over 1 kHz under mechanically deformed conditions facilitates conformal electronic sensors at the machine/human interface. Finally, a mechanically stretchable, flexible, and skin-conformal photoplethysmogram (PPG) device with higher sensitivity than those of rigid devices is demonstrated, through conformal adherence to the flexuous surface of a fingerprint.
KW - Flexible photodetectors
KW - Mechanical conformability
KW - Near infrared photodetectors
KW - Regioregular polymers
KW - Ultrathin photonic devices
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U2 - 10.1002/adma.201802359
DO - 10.1002/adma.201802359
M3 - Article
AN - SCOPUS:85050381032
SN - 0935-9648
VL - 30
JO - Advanced Materials
JF - Advanced Materials
IS - 34
M1 - 1802359
ER -
