Short‐Wave Infrared Sensor by the Photothermal Effect of Colloidal Gold Nanorods

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 14; no. 16; pp. e1704013 - n/a
• Main Authors: Xiang, Hengyang, Niu, Tingting, Schoenauer Sebag, Mathilde, Hu, Zhelu, Xu, Xiangzhen, Billot, Laurent, Aigouy, Lionel, Chen, Zhuoying
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.04.2018; Wiley-VCH Verlag
• Subjects: Colloiding; Energy gap; Engineering Sciences; Gold; gold nanoparticles; Infrared detectors; Materials; Micro and nanotechnologies; Microelectronics; Nanorods; Nanotechnology; Optics; photodetection; Photon absorption; Photonic; Photonic band gaps; Photothermal conversion; photothermal effect; short‐wave infrared; Thermal energy; Thermistors; short-wave infrared; photodetection; gold nanoparticles; photothermal effect; gold nanoparticles photothermal effect short-wave infrared photodetection
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201704013

Photodetection in the short‐wave infrared (SWIR) spectrum is a challenging task achieved often by costly low bandgap compound semiconductors involving highly toxic elements. In this work, an alternative low‐cost approach is reported for SWIR sensors that rely on the plasmonic‐induced photothermal effect of solution‐processed colloidal gold nanorods (Au NRs). A series of uniform solution‐processed Au NRs of various aspect ratios are prepared exhibiting a strong and well‐defined longitudinal localized surface plasmon resonance (L‐LSPR) maximum from 900 nm to 1.3 µm. A hybrid device structure is fabricated by applying Au NRs on the surface of a thermistor. Under a monochromatic illumination, hybrid Au‐NR/thermistor devices exhibit a clear photoresponse in the form of photoinduced resistance drop in the wavelength window from 1.0 to 1.8 µm. The photoresponsivity of such hybrid devices reaches a maximum value of 4.44 × 107 Ω W−1 at λ = 1.4 µm (intensity = 0.28 mW cm−2), a wavelength in agreement with the L‐LSPR of the Au NRs applied. Colloidal Au NRs, capable to perform fast conversion between photon absorption and thermal energy, thus open an interesting avenue for alternative low‐cost SWIR photodetection. Hybrid devices based on solution‐processed colloidal gold nanorods and a thermistor are fabricated to harvest the plasmonic‐induced photothermal effect for photodetection. Clear photoresponse is observed in these devices in the short‐wave IR wavelength window from 1.0 to 1.8 µm.