7 research outputs found
Graphene-perovskite fibre photodetectors
The integration of optoelectronic devices, such as transistors and
photodetectors (PDs), into wearables and textiles is of great interest for
applications such as healthcare and physiological monitoring. These require
flexible/wearable systems adaptable to body motions, thus materials conformable
to non-planar surfaces, and able to maintain performance under mechanical
distortions. Here, we prepare fibre PDs combining rolled graphene layers and
photoactive perovskites. Conductive fibres (500/cm) are made by
rolling single layer graphene (SLG) around silica fibres, followed by
deposition of a dielectric layer (AlO and parylene C), another
rolled SLG as channel, and perovskite as photoactive component. The resulting
gate-tunable PDs have response time5ms, with an external
responsivity22kA/W at 488nm for 1V bias. The external responsivity is two
orders of magnitude higher and the response time one order of magnitude faster
than state-of-the-art wearable fibre based PDs. Under bending at 4mm radius, up
to80\% photocurrent is maintained. Washability tests show72\% of
initial photocurrent after 30 cycles, promising for wearable applications
Graphene-black phosphorus printed photodetectors
Layered materials (LMs) produced by liquid phase exfoliation (LPE) can be used as building blocks for optoelectronic applications. However, when compared with mechanically exfoliated flakes, or films prepared by chemical vapor deposition (CVD), LPE-based printed optoelectronic devices are limited by mobility, defects and trap states. Here, we present a scalable fabrication technique combining CVD with LPE LMs to overcome such limitations. We use black phosphorus inks, inkjet-printed on graphene on Si/SiO2, patterned by inkjet printing based lithography, and source and drain electrodes printed with an Ag ink, to prepare photodetectors (PDs). These have an external responsivity (R ext)∼337 A W−1 at 488 nm, and operate from visible (∼488 nm) to short-wave infrared (∼2.7 µm, R ext ∼ 48 mA W−1). We also use this approach to fabricate flexible PDs on polyester fabric, one of the most common used in textiles, achieving R ext ∼ 6 mA W−1 at 488 nm for an operating voltage of 1 V. Thus, our combination of scalable CVD and LPE techniques via inkjet printing is promising for wearable and flexible applications
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Graphene‐Perovskite Fibre Photodetectors
Publication status: PublishedFunder: Royal Society; doi: http://dx.doi.org/10.13039/501100000288The integration of optoelectronic devices, such as transistors and photodetectors (PDs), into wearables and textiles is of great interest for applications such as healthcare and physiological monitoring. These require flexible/wearable systems adaptable to body motions, thus materials conformable to non‐planar surfaces, and able to maintain performance under mechanical distortions. Here, fibre PDs are prepared by combining rolled graphene layers and photoactive perovskites. Conductive fibres (~500 Ωcm‐1) are made by rolling single‐layer graphene (SLG) around silica fibres, followed by deposition of a dielectric layer (Al2O3 and parylene C), another rolled SLG as a channel, and perovskite as photoactive component. The resulting gate‐tunable PD has a response time~9ms, with an external responsivity~22kAW‐1 at 488nm for a 1V bias. The external responsivity is two orders of magnitude higher, and the response time one order of magnitude faster, than state‐of‐the‐art wearable fibre‐based PDs. Under bending at 4mm radius, up to~80% photocurrent is maintained. Washability tests show~72% of initial photocurrent after 30 cycles, promising for wearable applications
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Graphene-black phosphorus printed photodetectors
Abstract
Layered materials (LMs) produced by liquid phase exfoliation (LPE) can be used as building blocks for optoelectronic applications. However, when compared with mechanically exfoliated flakes, or films prepared by chemical vapor deposition (CVD), LPE-based printed optoelectronic devices are limited by mobility, defects and trap states. Here, we present a scalable fabrication technique combining CVD with LPE LMs to overcome such limitations. We use black phosphorus inks, inkjet-printed on graphene on Si/SiO2, patterned by inkjet printing based lithography, and source and drain electrodes printed with an Ag ink, to prepare photodetectors (PDs). These have an external responsivity (R
ext)∼337 A W−1 at 488 nm, and operate from visible (∼488 nm) to short-wave infrared (∼2.7 µm, R
ext
∼
48 mA W−1). We also use this approach to fabricate flexible PDs on polyester fabric, one of the most common used in textiles, achieving R
ext
∼
6 mA W−1 at 488 nm for an operating voltage of 1 V. Thus, our combination of scalable CVD and LPE techniques via inkjet printing is promising for wearable and flexible applications.</jats:p