Advanced pyroelectric materials for energy harvesting and sensing applications

Ferroelectricity-Driven Self-Powered Weak Temperature and Broadband Light Detection in MoS2/CuInP2S6/WSe2 van der Waals Heterojunction Nanoarchitectonics

“…When the temperature fluctuates because of the light, the pyroelectric effect works in the MoS 2 /CIPS/WSe 2 vdW heterojunction, whose working mechanism is shown in Figure g–i. Initially, the spontaneous polarization of heterojunction is constant, the electric dipole arrangement remains balanced (d T /d t = 0), and no current is generated when the circuit is closed (Figure g). ,, However, when the light is turned on, the heterojunction captures the light energy and converts it to heat (d T /d t >0), and the random oscillation state of electric dipoles is disturbed, resulting in a decrease in spontaneous polarization and a decrease in bound charge, then generating a pyroelectric current (Figure h). − When the light is turned off, the heterojunction surface temperature decreases (d T /d t <0), resulting in an increase in spontaneous polarization and an increase in bound charge. ,, Thus, a reverse pyroelectric current is generated (Figure i). In the application of the MoS 2 /CIPS/WSe 2 vdW heterojunction, both pyroelectric and bulk photovoltaic effects are important to realize the photodetection performance.…”

“…The polarization charge intensity of the dielectric is demonstrated by the pyroelectric coefficient p , which describes the proportional relationship between spontaneous polarization change and temperature . The precise quantification of p is essential for the development and improvement of devices such as infrared radiation sensors, temperature detectors, energy harvesters, and hydrogen production. − Assuming a constant pyroelectric effect and a consistent temperature of the pyroelectric material, the pyroelectric current ( I py ) is calculated with this equation: I py = pS (d T /d t ), where S is the active area and d T /d t is the temperature change rate . Since J py is equal to I py divided by S , p can also be written as p = J py /(d T /d t ).…”

“…However, when the CIPS is too thick, only the surface absorbs the heat, and the heat is difficult to transfer to the entire volume, so the p is reduced. Figure c depicts the p- value of the MoS 2 /CIPS/WSe 2 vdW heterojunction under a 660 nm laser with the CIPS thickness of 20, 45, 68, and 70 nm compared with those of other pyroelectric materials, such as ZnO, LiTaO 3 , β′-In 2 Se 3 , PZT, α-PbO, PVDF, and P­(VDF-TrFE), and their thicknesses are indicated. Compared with these typical pyroelectric materials, the p of the MoS 2 /CIPS/WSe 2 vdW heterojunction is larger than those of many pyroelectric materials due to the total effect of the polarization of CIPS and the interface junctions.…”

“…54−57 Assuming a constant pyroelectric effect and a consistent temperature of the pyroelectric material, the pyroelectric current (I py ) is calculated with this equation: I py = pS(dT/dt), where S is the active area and dT/dt is the temperature change rate. 35 Since J py is equal to I py divided by S, p can also be written as p = J py /(dT/dt). Therefore, based on the equation, the p of the MoS 2 /CIPS/WSe 2 vdW heterojunction at 405, 660, 808, and 1064 nm lasers can be calculated according to the J py in Figure 3a−d, respectively, and we selected the corresponding part of heating to extract pyroelectric coefficients.…”

Pyroelectric based energy harvesting devices: hybrid structures and applications

“…Furthermore, material integration and interface engineering can be improved to improve energy transfer efficiency between the various components in the device. 96–98…”