Narrow bandgap semiconductors like indium antimonide (InSb) are very suitable for high-performance room temperature infrared photodetectors, but the fragile nature of the wafer materials hinders their application as flexible/wearable devices. Here, we present a method to fabricate a photodetector device of assembled crystalline InSb nanowire (NW) arrays on a flexible substrate that balances high performance and flexibility, facilitating its application in wearable devices. The InSb NWs were synthesized by means of a vapor–liquid–solid technique, with gold nanoclusters as seeding particles. The morphological and crystal properties were investigated using scanning electron microscopy, x-ray diffraction and high-resolution transmission electron microscopy, which revealed the unique spike shape and high crystallinity with (111) and (220) planes of InSb NWs. The flexible infrared photodetector devices were fabricated by transferring the NWs onto transparent and stretchable polydimethylsiloxane substrate with pre-deposited gold electrodes. Current versus time measurement of the photodetector devices under light showed photoresponsivity and sensitivity to mid-infrared at bias as low as 0.1 V while attached to curved surfaces (suitable for skin implants). A high-performance NW device yielded efficient rise and decay times down to 1 s and short time lag for infrared detection. Based on dark current, calculated specific detectivity of the flexible photodetector was 1.4 × 1012 Jones. The performance and durability render such devices promising for use as wearable infrared photodetectors. © 2021 IOP Publishing Ltd.
Bibliographical noteWe acknowledge support from the National Key R&D Program of China (Grant No. 2017YFA0206202), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB30000000), the National Natural Science Foundation of China (Grant Nos. 12074302, 11704303), and the support of UAE University through the grant UPAR 12S013. We thank the Instrument Analysis Center of Xi’an Jiaotong University for their assistance with FESEM, TEM and XRD analysis.
- Flexible devices
- Indium antimonide (InSb)
- Infrared photodetector