Plasmon Coupled Colloidal Gold Nanorods for Near‐Infrared and Short‐Wave‐Infrared Broadband Photodetection

Abstract

Solution‐processed plasmonic colloidal gold nanorods (Au NRs) are promising candidates leading to new photodetection applications. While plasmonic Au NRs of a specific dimension will lead to a well‐defined optical extinction due to the localized surface plasmon resonance, in photodetection applications broadband functioning is often desired. In this work, a broadband optical extinction is achieved from λ = 400 to 2000 nm by coupling colloidal Au NRs of various dimensions in a thin film form. Such an Au NR thin film is further applied on a platinum (Pt) electrode to fabricate hybrid Au‐NR/Pt photodetectors. On these hybrid Au‐NRs/Pt devices, thanks to the plasmonic‐induced photothermal effect, a clear broadband photoresponse is demonstrated covering the near‐infrared (NIR) and short‐wave‐infrared (SWIR) spectrum from λ = 800 to 2000 nm, with a <200 µs fast photoresponse time. This work suggests that suitably coupled plasmonic colloidal Au NRs and their strong photothermal effect are promising strategies for the future development of low‐cost and broadband NIR/SWIR photodetection.

Superparticles of gold nanorods with controllable bandwidth and spectral shape for lipophilic SERS

“…The controllable bandwidth is mainly achieved through the tunability of GNRs, which allows for extinction from visible light to near-infrared. 32,40 Fig. 2c displays the measured and calculated spectra dispersed in an ethanol solution, demonstrating good agreement between the experimental and calculated results.…”

“…† When the distance between GNRs is less than 10 nm, a strong coupling effect occurs between them, leading to changes in their absorption and scattering characteristics. 39,40 Coating mesoporous silica on the surface of GNRs can effectively control the spacing between GNR monomers, thereby reducing the coupling effect. The spectrum of GNRs@SiO 2 is only slightly redshifted due to the change in refractive index.…”

Plasmonic Photoresistor Based on Interconnected Metal‐Semiconductor Grating

“…[ 8 ] The nonradiative decay of the plasmons results in the generation of hot electrons [ 9,10 ] that get transferred across the Schottky barrier at the metal‐semiconductor interface and can be detected as a photocurrent. [ 11,12 ] Most of these devices contain plasmonic nanostructures in the form of nanoparticles, [ 13 ] nanorods, [ 11,14 ] nanowires, [ 15,16 ] either arranged randomly [ 13 ] or in arrays. [ 11,17 ] The advantages of using periodic arrays involve the excitation of diffraction‐mediated plasmon modes such as surface lattice resonances, [ 18,19 ] which tend to localize fields more strongly, resulting in enhanced charged transfer.…”

Predictable and adjustable broadband gold nanorods for photothermal effects and foldable performances

“…To address the issue of narrowband characteristics, researchers have developed broadband nanostructures using gold nanoparticles. For instance, Xiang et al [33] mixed GNRs of three different sizes and deposited them on a glass sheet to create a film with broadband properties. They then placed GNRs on Pt electrodes for near-infrared and short-wave infrared broadband photoelectric detection.…”