Ultraflexible PEDOT:PSS/Helical Carbon Nanotubes Film for All-in-One Photothermoelectric Conversion

Abstract

Photothermoelectric (PTE) conversion can achieve the recovery of low-quality light or heat efficiently. Much effort has been devoted to the exploitation of the inorganic heterogeneous asynchronous (separate) PTE conversion system. Here, a full organic PTE film with a pseudobilayer architecture (PBA) according to the homogeneous synchronous (all-in-one) PTE conversion hypothesis was prepared via successive drop-casting a PEDOT:PSS/helical carbon nanotube (HCNT) mixture and PEDOT:PSS onto a vacuum ultraviolet treated substrate. Our results prove that the heptagon−pentagon pairs embedded in HCNTs promote a denser arrangement of the molecular chains of PEDOT, which enhances the crystallinity and affects the thermoelectric properties. The weak connection and hollow structure of HCNTs inhibit the dissipation of heat, and the zT value of the film reaches over 0.01. The PBA film shows better photothermal conversion performance than a neat PEDOT:PSS film and stably generates a temperature difference of over 25.68 °C without external cooling. A flexible PTE chip demo was manufactured, and the ideal opencircuit voltage (simulated via COMSOL) of that reaches over 1.5 mV under weak NIR stimulation (83.12 mW/cm 2 ), which is the best value reported for an organic all-in-one PTE device, and the real maximum output power reaches 2.55 nW (166.01 mW/cm 2 ). The chip has incredible ultraflexibility, and its inner resistance changes less than 1.42% after 10000 bending cycles and displays ultrahigh stability (similarity >90%) in a continuous periodic output. Our work fills the deficit of homogeneous synchronous PTE research for a PEDOT:PSS composite and is a preliminary attempt in an ultraflexible integrated all-in-one PTE chip design.

Ag2Se/nylon self-supporting composite films for wearable photo-thermoelectric generators with high output characteristics

“…43 A very high output power of 8.3 and 15.8 mW can be reached when this PTEG is irradiated with light intensities of 100 and 150 mW cm À2 , respectively. The power enhancement of the PTEG can be easily obtained by increasing the number of legs, so the singleleg output power of 2.1 and 4.0 mW with light intensities of 100 and 150 mW cm À2 of this device is used to compare it with the vast majority of the currently reported PTEGs, 13,40,42,43,[56][57][58] as shown in Fig. 5g.…”

“…The detailed structure of the device has been represented in detail in our previous work, proving that the system possesses a high degree of accuracy. 13,39 Finally, the thermal conductivities of the overall lm were calculated by using k ¼ D Â C Â r, where D and C represent the thermal diffusion coefficient and specic heat capacity, respectively, which were measured by the laser ash method (LFA 467 HyperFlash, NETZSCH Inc., Germany) and differential scanning calorimetry (DSC 204 F1 Phoenix, NETZSCH Inc., Germany). It is worth noting that all samples were sprayed with graphite during the former test to prevent light leakage and the specic heat capacity tests were in accordance with the standard ASTM E1269.…”

“…Depending on the location where the PT and TE effects occur, PTEGs are divided into heterogeneous asynchronous and homogeneous synchronous devices. 13 The construction of the former is based on the introduction of an additional PT layer to establish an effective temperature difference, and the greatest advantage of this structure is that the properties of the PT and TE layers can be regulated separately to achieve the construction of high-performance generators. For instance, a heterogeneous asynchronous PTEG was obtained in our previous study by optimizing the non-self-supporting Ag 2 Se TE layer and the polypyrrole (PPy) PT layer, respectively.…”

“…[1][2][3][4][5][6][7] Unlike traditional chemical batteries that are prone to failure and require frequent replacement, some TE generators can now achieve a conversion efficiency of 1% of the body's energy to meet the needs of most implanted and convenient electronic devices, [8][9][10] such as wireless sensing networks, 11 smartwatches and activity trackers. 9 The dimensionless gure of merit ZT is the most important indicator of TE material properties, 12 which dened as S 2 sT/k, where S (mV K À1 ) is the Seebeck coefficient, s (S cm À1 ) and T (K) represent the electrical conductivity and absolute temperature, respectively, and k (W m À1 K À1 ) is the overall thermal conductivity in the direction of heat ow, [13][14][15] which is composed of lattice thermal conductivity (k l ) and carrier thermal conductivity (k e ). 16 The power factor (PF ¼ S 2 s) is also frequently used in some studies to evaluate the performance of TE materials.…”

“…16 The power factor (PF ¼ S 2 s) is also frequently used in some studies to evaluate the performance of TE materials. [13][14][15] Therefore, optimization of the mutually unfavorable resistivity, Seebeck coefficient and thermal conductivity as a group is required to boost the ZT. Recently, several different concepts and strategies have been proposed in related research to make the material exhibit both high electrical conductivity and low thermal conductivity, such as electron energy ltering, phonon-glass electron-crystals, multicomponent nanostructures, and resonant energy level impurities.…”