A Rapid Response Thin-Film Plasmonic-Thermoelectric Light Detector

Abstract

Light detection and quantification is fundamental to the functioning of a broad palette of technologies. While expensive avalanche photodiodes and superconducting bolometers are examples of detectors achieving single-photon sensitivity and time resolutions down to the picosecond range, thermoelectric-based photodetectors are much more affordable alternatives that can be used to measure substantially higher levels of light power (few kW/cm2). However, in thermoelectric detectors, achieving broadband or wavelength-selective performance with high sensitivity and good temporal resolution requires careful design of the absorbing element. Here, combining the high absorptivity and low heat capacity of a nanoengineered plasmonic thin-film absorber with the robustness and linear response of a thermoelectric sensor, we present a hybrid detector for visible and near-infrared light achieving response times of the order of 100 milliseconds, almost four times shorter than the same thermoelectric device covered with a conventional absorber. Furthermore, we show an almost two times higher light-to-electricity efficiency upon replacing the conventional absorber with a plasmonic absorber. With these improvements, which are direct results of the efficiency and ultra-small thickness of the plasmonic absorber, this hybrid detector constitutes an ideal component for various medium-intensity light sensing applications requiring spectrally tailored absorption coatings with either broadband or narrowband characteristics.

Hybrid Plasmonic and Pyroelectric Harvesting of Light Fluctuations

“…The plasmonic nanostructures strongly absorb light through resonant excitation of plasmons (collective charge oscillations), which leads to local heating of both the nanostructure and the surrounding environment . Such light‐induced plasmonic heating can enable a wide range of applications, including solar‐powered autoclaving, plasmon‐driven thermophoresis, seawater catalysis, plasmonic‐thermoelectric light detection, and desalination concepts . In our hybrid plasmonic‐pyroelectric device (referred to as hybrid device below), plasmonic heating of a gold nanodisk array modulates the temperature of a pyroelectric polymer.…”

Photo-Thermoelectric Conversion of Plasmonic Nanohole Array

“…Our device consisted of a thin film of a thermoelectric material embedded with plasmonic atoms that generated plasmonic local heating and created a thermal gradient inside the film as a consequence of light detection by absorption, resulting in Seebeck voltage generation. Similarly, many studies of light detection via thermoelectric conversion, in, for example, carbon nanotubes [8,9], graphene [10,11], carbon sprays [12], and commercial thermoelectric devices [13] triggered by metal-nanostructure plasmon resonance, have been reported. These light detection systems were based on thermoelectric materials combined with plasmonic atoms used as light receivers.…”

Plasmon‐Enhanced Photodetection in Ferromagnet/Nonmagnet Spin Thermoelectric Structures

“…The thermally generated voltage is proportional to the Seebeck coefficient S of the material and temperature difference Δ T . When the temperature difference is developed optically, the capability to transduce optical signals to electrical signals via the mediation of thermoelectricity, called the photothermoelectric (PTE) effect, can be utilized for photodetection …”