Thermodiffusion‐Assisted Pyroelectrics—Enabling Rapid and Stable Heat and Radiation Sensing

Abstract

Sensors for monitoring temperature, heat flux, and thermal radiation are essential for applications such as electronic skin. While pyroelectric and thermoelectric effects are suitable candidates as functional elements in such devices, both concepts show individual drawbacks in terms of zero equilibrium signals for pyroelectric materials and small or slow response of thermoelectric materials. Here, these drawbacks are overcome by introducing the concept of thermodiffusion-assisted pyroelectrics, which combines and enhances the performance of pyroelectric and ionic thermoelectric materials. The presented integrated concept provides both rapid initial response upon heating and stable synergistically enhanced signals upon prolonged exposure to heat stimuli. Likewise, incorporation of plasmonic metasurfaces enables the concept to provide both rapid and stable signals for radiation-induced heating. The performance of the concept and its working mechanism can be explained by ion-electron interactions at the interface between the pyroelectric and ionic thermoelectric materials.

Ultrasensitive electrolyte-assisted temperature sensor

“…A significant fraction of the plasmons decay via absorption and local heat generation 31,32 , which increases the temperature and induces signals in the sensor. The principle of using thermoplasmonic nanohole films to convert light to electrical signals follows our previous work on radiationinduced heat sensing [33][34][35] . Finally, we evaluate the EATS concept for heat mapping using sensor pixel arrays, and demonstrate its capability to detect human touch.…”

Hybrid Plasmonics for Energy Harvesting and Sensing of Radiation and Heat

“…[131] In this thesis, a composite thermoelectric gel (Figure 3-4c . [132] The negative sign of the Seebeck coefficient comes from dissociated anions that thermodiffuse towards the colder side of the gel, when it is subjected to a temperature gradient. The thermodiffusing ions in ionic thermoelectric materials cannot pass into an external circuit of a TEG, instead they accumulate at the interface of the metal electrode and the ionic thermoelectric material.…”

“…A lateral device as depicted in Figure 4 Schematic illustration of the Seebeck coefficient measurement setup. [132] Chapter 5: Summary of the appended papers The plasmonic heating in the gold nanodisk arrays is another influential factor on the current density generated by the plasmo-pyro hybrid device. Harvesting energy from light using plasmonic nanostructures in inorganic hybrid systems have been studied earlier.…”

Optically Governed Dynamic Surface Charge Redistribution of Hybrid Plasmo‐Pyroelectric Nanosystems

“…More recently, with band bending alteration, the flow direction of optically excited electrons was demonstrated to be controllable in ferroelectric–metal systems, which has further expanded the potential strategies to manipulate the charge density of the materials. However, due to the wide bandgap (2.7–4 eV) of ferroelectric materials, they absorb less than 20% of the solar spectrum, resulting in unfavorable low charge density .…”

“…[11] As the performance of an energy harvester is related to its charge density, significant efforts have been made to increase the charge density by means of poling, material selection, architecture optimization, and surface modification. [12,13] More recently, with band bending alteration, the flow direction of optically excited electrons was demonstrated to be controllable in ferroelectric-metal systems, [10,11,[14][15][16] which has further expanded the potential strategies to manipulate the charge density of the materials. However, due to the wide bandgap (2.7-4 eV) of ferroelectric materials, they absorb less than 20% of the solar spectrum, resulting in unfavorable low charge density.…”