High-performance Thermoelectric Generator Research Articles

π-Conjugated metallo-copolymer/SWCNT composites for high performance thermoelectric generators

Organic materials have attracted extensive attention in flexible thermoelectric generators due to their solution processability, low thermal conductivity and high flexibility. However, their thermoelectric performances are still far behind those of the inorganic counterparts (e.g. Bi2Te3, PbTe and other related alloys). Here, by virtue of the dual advantages of both inorganic and organic materials, three Pt (II)-containing diketopyrrolopyrrole (DPP) based donor−acceptor (D−A)-type π-conjugated metallo-copolymers (P1Pt, P2Pt and P3Pt) are designed and synthesized, and they are compared with their control copolymers without Pt (II)-coordination (P1, P2 and P3). It is shown that Pt (II) centers and copolymerized molecular structures play important roles in tuning the bandgap and coplanarity. A large Fermi level shift is observed after doping with single-walled carbon nanotubes (SWCNTs) in the copolymers. As expected, the introduction of Pt (II)-side chains and doping of SWCNTs into copolymers could significantly improve the power factor (PF), which reaches the highest value of 276.5 ± 26.6 μW m−1 K−2 for P3Pt/60 wt% SWCNTs. The corresponding p-type thermoelectric generator exhibits a large output power of up to 0.55 μW under a 109 K temperature gradient. Our results can provide a pathway for designing and preparing efficient thermoelectric materials and flexible thermoelectric generators.

Stretchable Thermoelectric Generators for Self‐Powered Wearable Health Monitoring

AbstractAs continuous wearable physiological monitoring systems become more ubiquitous in healthcare, there is an increasing need for power sources that can sustainably power wireless sensors and electronics for long durations. Wearable energy harvesting with thermoelectric generators (TEGs), in which body heat is converted to electrical energy, presents a promising way to prolong wireless operation and address battery life concerns. In this work, high performance TEGs are introduced that combine 3D printed elastomers with liquid metal epoxy polymer composites and thermoelectric semiconductors to achieve elastic compliance and mechanical compatibility with the body. The thermoelectric properties are characterized in both energy harvesting (Seebeck) and active heating/cooling (Peltier) modes, and examine the performance of wearable energy harvesting under various conditions such as sitting, walking, and running. When worn on a user's forearm while walking outside, the TEG arrays are able to power circuitry to collect photoplethysmography (PPG) waveform data with a photonic sensor and wirelessly transmit the data to an external PC using an on‐board Bluetooth Low Energy (BLE) radio. This represents a significant step forward on the path to sustainable body‐worn smart electronics.

Optimization of a unileg thermoelectric generator by the combination of Taguchi method and evolutionary neural network for green power generation

The performance optimization of thermoelectric generators (TEGs) is crucial for efficiently converting waste heat to green energy. This study analyzes the performance and thermal stress of a unileg thermoelectric module by combining the Taguchi method, analysis of variance (ANOVA), and artificial neural network. The results of the Taguchi method indicate that the leg geometry exerts a negligible effect on output power (OP) and conversion efficiency but significantly affects the thermal stress (TS). The analysis of the objective function (maximum OP-to-maximum TS ratio, denoted by P/S) reveals the optimal configuration results in a P/S value of 0.01255 W‧MPa−1, accompanied by a maximum output power (2.9 W) and thermal stress (232.32 MPa). The maximum thermal stress of the rectangle TE leg (182.29 MPa) is less than that of the triangle (279.85 MPa) by 34.86 %. The Taguchi method, analysis of variance, and artificial neural network have the same sensitivity order on P/S with leg height > leg geometry > copper thickness > ceramic thickness. Furthermore, an evolutionary neural network (ENN) method with five-step optimization from 4000 datasets has been developed to improve machine learning prediction. The average error of P/S value and conversion efficiency from ENN is 1.61 % and 0.35 %, respectively. However, for the ENN predictions, the relative errors of P/S value and efficiency between predictions and simulations are 1.28 % and 0.19 %, respectively. In conclusion, this work has demonstrated the numerical optimization of the performance of unileg TEM for the first time. The use of ENN can predict the performance of TEM precisely, saving running time and markedly reducing computational costs. Moreover, the results are conducive to designing high-performance TEGs with long lifespans.

An n-Type Conjugated Polymer with Low Crystallinity for High-Performance Organic Thermoelectrics.

Conjugated polymers (CPs) with low crystallinity are promising candidates for application in organic thermoelectrics (OTEs), particularly in flexible devices, because the disordered structures of these CPs can effectively accommodate dopants and ensure robust resistance to bending. However, n-doped CPs usually exhibit poor thermoelectric performance, which hinders the development of high-performance thermoelectric generators. Herein, we report an n-type CP (ThDPP-CNBTz) comprising two acceptor units: a thiophene-flanked diketopyrrolopyrrole and a cyano-functionalized benzothiadiazole. ThDPP-CNBTz shows a low LUMO energy level of below -4.20 eV and features low crystallinity, enabling high doping efficiency. Moreover, the dual-acceptor design enhances polaron delocalization, resulting in good thermoelectric performance. After n-doping, ThDPP-CNBTz exhibits an average electrical conductivity (σ) of 50.6 S cm-1 and a maximum power factor (PF) of 126.8 μW m-1 K-2, which is among the highest values reported for solution-processed n-type CPs to date. Additionally, a solution-processed flexible OTE device based on doped ThDPP-CNBTz exhibits a maximum PF of 70 μW m-1 K-2; the flexible device also shows remarkable resistance to bending strain, with only a marginal change in σ after 600 bending cycles. The findings presented in this work will advance the development of n-type CPs for OTE devices, and flexible devices in particular.

Effect of heat dissipation on the performance of thermoelectric generator

Thermoelectric generators (TEGs) can directly convert heat into electricity with the advantages of ultra-silence, fast response, and high-power density, but the practical application is limited by their low conversion efficiency. We find that the heat dissipation caused by heat convection and heat exchange is an important factor in inhibiting the conversion efficiency. To reveal the effect of heat dissipation on the performance of TEGs, the theoretical model for the thermal-electric coupling of TEGs is built, while experimental research is taken to determine key parameters of heat transfer in theory and to verify theoretical models. Results show that both heat convection and heat exchange in TEGs severely inhibit the conversion efficiency by improving the heat consumption, but have no effect on the output power for a determined temperature gradient. According to theoretical results, the size of TEG is designed to improve the conversion efficiency by suppressing the impact of heat dissipation, while a vacuum encapsulation is proven to have the ability to eliminate both heat convection and heat exchange. As a result, the conversion efficiency of a Bi2Te3-based TEG is improved by 52% from the commercial TEGs. These findings provide a theoretical basis and guidance for obtaining high-performance TEGs.

A Review of Thermoelectric Generators in Automobile Waste Heat Recovery Systems for Improving Energy Utilization

With the progress of modern times, automobile technology has become integral to human society. At the same time, the need for energy has also grown. In parallel, the total amount of waste energy that is liberated from different parts of the automobile has also increased. In this ever-increasing energy demand pool, future energy shortages and environmental pollution are the primary concerns. A thermoelectric generator (TEG) is a promising technology that utilizes waste heat and converts it into useful electrical power, which can reduce fuel consumption to a significant extent. This paper comprehensively reviews automobile thermoelectric generators and their technological advancements. The review begins by classifying different waste heat technologies and discussing the superiority of TEGs over the other existing technologies. Then, we demonstrate the basic concept of and advancements in new high-performance TEG materials. Following that, improvements and associated challenges with various aspects, such as the heat exchanger design, including metal foam, extended body, intermediate fluid and heat pipe, leg geometry design, segmentation, and multi-staging, are discussed extensively. Finally, the present study highlights research guidelines for TEG design, research gaps, and future directions for innovative works in automobile TEG technologies.

High-Performance thermoelectric generator based on n-Type flexible composite and its application in Self-Powered temperature sensor

Thermoelectric generators (TEGs) present a promising alternative to conventional power generation technologies for powering low-power wearable electronics. However, there are few n-type organic materials with high thermoelectric and mechanical performance. In this study, a polymer (PEI-PFA) via low temperature polycondensation between polyethyleneimine (PEI) and paraformaldehyde (PFA) is synthesized, and this is the first reported polymer which can be not only used as a novel n-type dopant of single-walled carbon nanotubes (SWCNTs) due to the PEI moieties, but also endow the composites with good flexibility due to the synthesized hemiaminal dynamic covalent networks. Subsequent addition of sodium hydroxide (NaOH) can further enhance the electron conductivity. The resulting SWCNT/PEI-PFA/NaOH composite film exhibits an excellent electrical conductivity of 1641.22 S cm−1, a power factor of 115.77 μW m−1 K−2, a tensile strength of 36.4 MPa, and flexibility up to 21 % strain. In addition, a self-powered sensor is assembled, which can efficiently monitor temperature changes and strain deformations. Moreover, a thermoelectric device containing five p-n junctions based on the pristine SWCNTs and SWCNT/PEI-PFA/NaOH composite is prepared, and a high output power of 5.33 μW at the temperature difference of 75.2 K is achieved. This work presents a promising approach to developing flexible n-type thermoelectric materials for self-powered wearable electronics.

Growth and characterization of Bi2Te2.70Se0.30 nanostructured materials by using a cost-effective chemical solution route

A chemical solution route was employed to successfully synthesize single-phase Bi2Te2.70Se0.30 nanostructured powders at room temperature, ensuring minimal contamination. The synthesized powders underwent a comprehensive analysis using a range of characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), ultraviolet-visible (UV) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, atomic-force microscopy (AFM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The temperature-dependent behaviors of electrical conductivity and the Seebeck coefficient were also explored. The findings revealed that the synthesized powders displayed consistent spherical morphology, with an average diameter of 68.42 nm. Additionally, they exhibited a band gap energy of 0.615 eV. This research highlights the significant improvement achieved by incorporating selenium into the Bi2Te2.70Se0.30 materials through this synthesis process. The EDAX analysis confirmed the stoichiometric atomic ratio of bismuth (Bi), tellurium (Te), and selenium (Se) elements. Furthermore, the TEM images revealed the presence of agglomeration within the powders, demonstrating a primary crystalline size characterized by relatively small dimensions. The emergence of a pronounced exothermic peak at around 650 K signaled the commencement of oxidation for the Bi2Te2.70Se0.30 material. In electrical measurement, a synergy was achieved between heightened electrical conductivity and a well-matched Seebeck coefficient, with the goal of enhancing energy conversion efficiency in TE applications. These findings demonstrate the potential of the synthesized powders for producing nanostructured thermoelectric (TE) materials with controlled grain sizes, which are essential for the fabrication of high-performance thermoelectric generators (TEGs).

3D Printing of Bi2Te3-Based Thermoelectric Materials with High Performance and Shape Controllability.

Thermoelectric (TE) energy conversion technology provides a promising way to improve the efficiency of fossil energy by generating electricity from low-grade waste heat. With regard to these applications, thermoelectric generators (TEGs) should be designed from system integration perspectives to simultaneously improve heat transfer efficiency and system simplification as well as the robust mechanical properties. However, typical TEGs fabricated by conventional methods barely accomplish such requirements. Herein, high-quality TEGs were assembled by combining the well-flowable spherical bismuth telluride (BT) powdered precursors and selective laser melting (SLM) technology. By optimizing the electronic and phonon transport properties through defect engineering driven by 3D printing, a high figure of merit was accomplished for 1.27 (p-type) and 1.13 (n-type) in BT. This achievement is primarily attributed to the nonequilibrium solidification mechanism, which leads to the formation of multiscale defects during the 3D printing process. The introduction of these multiscale defects enables the effective scattering of wide frequency phonons, leading to a substantial reduction in lattice thermal conductivity. Meanwhile, robust mechanical properties were obtained in the printed p-type/n-type BT TE materials parallel to the building direction (BD) with a compressive strength reaching 257/250 MPa by employing the fine grain structure and the high density of nanotwins introduced during the SLM process. A well shape-controllable and high-performance TEG was designed using 3D-printed BT half-rings, and an output power of 134 mW was achieved at a temperature gradient of 38.9 °C. Our study opens a new route for the great potential of TE materials based on standard commercial SLM 3D printing technology for low-grade waste heat emitted from structures with heterogeneous shapes.

Avoiding errors in efficiency measurements of high-performance thermoelectric generator modules: Toward best practices for materials researchers

The recent surge in reports on high-efficiency thermoelectric generator modules brings two conflicting feelings: excitement and confusion. The confusion comes from the fact that there is no widely accepted standard protocol for efficiency measurement. The standardised protocol should be easy to follow for materials researchers, who fabricate and measure generator modules using emerging thermoelectric materials of their own. Here, as a balanced method in terms of reliability and simplicity, we demonstrate straightforward measurement setup and procedure. To compare thermoelectric generator modules with various materials, size, and measurement conditions, we propose to explicitly distinguish intrinsic contributions to the efficiency from extrinsic effects such as surface radiation loss. We confirm that too quick measurements before attaining thermal stabilization can cause serious overestimation of the conversion efficiency by up to 27%. To reliably evaluate the maximum efficiency and output power, we adopt a nonlinear current sweep to directly measure the output power and heat flow in a short timeframe. We believe that this work will promote discussion among the community to achieve consensus on the efficiency measurements of thermoelectric modules, which will enable detailed comparative analyses of the results reported by various research groups.

Design a high-performance thermoelectric generator by analyzing industrial heat transfer

Industrial production will release a large amount of waste heat into the environment and cause serious energy waste. Currently, most waste heat recovery technologies cannot directly convert waste heat into energy required for industrial production, and there is a problem of low energy conversion efficiency problem. Thermoelectric conversion technology can convert industrial waste heat into electrical energy and directly use it in industrial production. This study uses a numerical method to analyze the heat transfer behavior between an industrial thermal environment and a thermoelectric generator (TEG). According to the numerical calculation results, the deficiencies of the original TEG are optimized, and a new TEG with high power generation performance and stability is designed. Finally, the accuracy of numerical calculation results and the industrial application feasibility of new TEG are verified through on-site tests. The results show that the power generation performance of the new TEG has been greatly improved, and it can operate stably for a long time in an industrial environment. The best economic benefit can be obtained by installing new TEGs in the x = 20 m-21 m, the power generation cost is 3.45$/W, and the total output power is 0.55 kW. The cost of power generation for new TEGs will increase as the installation area increases. When new TEGs are installed in the x = 20 m-24 m, the power generation cost is 3.97$/W, and the total output power is 1.96 kW. It can be known from the on-site testing results that the new TEG has high practical value and can be widely used in industrial waste heat recovery.

High-Performance Wearable Bi2Te3-Based Thermoelectric Generator

Wearable thermoelectric generators (w-TEGs) convert thermal energy into electrical energy to realize self-powering of intelligent electronic devices, thus reducing the burden of battery replacement and charging, and improving the usage time and efficiency of electronic devices. Through finite element simulation, this study successfully designed high-performance thermoelectric generator and made it into wearable thermoelectric module by adopting “rigid device—flexible connection” method. It was found that higher convective heat transfer coefficient (h) on cold-end leads to larger effective temperature difference (ΔTeff) and better power generation performance of device in typical wearable scenario. Meanwhile, at same h on the cold-end, longer TE leg length leads to larger ΔTeff established at both ends of device, larger device output power (Pout) and open-circuit voltage (Uoc). However, when the h increases to a certain level, optimization effect of increasing TE leg length on device power generation performance will gradually diminish. For devices with fixed temperature difference between two ends, longer TE leg length leads to higher resistance of TEGs, resulting in lower device Pout but slight increase in Uoc. Finally, sixteen 16 × 4 × 2 mm2 TEGs (L = 1.38 mm, W = 0.6 mm) and two modules were fabricated and tested. At hot end temperature Th = 33 °C and cold end temperature Tc = 30 °C, the actual maximum Pout of the TEG was about 0.2 mW, and the actual maximum Pout of the TEG module was about 1.602 mW, which is highly consistent with the simulated value. This work brings great convenience to research and development of wearable thermoelectric modules and provides new, environmentally friendly and efficient power solution for wearable devices.

High-Performance Functionalized Mg2Si0.9Sn0.1 Thermoelectric Leg Synthesis by a Single-Step Reactive SPS Process

Contact electrodes and their adequate joining are the main bottlenecks in realizing low-cost Mg2(Si,Sn) thermoelectric materials for thermoelectric generator applications. The resistance and diffusion chemistry between the thermoelectric elements and contact electrodes play an essential role in achieving high-performance thermoelectric generators for intermediate-temperature applications. A facile single-step spark plasma sintering process was employed to fabricate Sb-doped Mg2Si0.9Sn0.1 and contact joining simultaneously. The single-step-processed thermoelectric element’s power output characteristics with three different contacts (Ni, MnSi, and FeSi2) were investigated by employing a thermoelectric conversion efficiency evaluation system. Our experimental strategy demonstrated that the single-step processing of Mg2(Si0.9Sn0.1)0.95Sb0.05/Ni joining imparts the lowest internal resistance and high-power output characteristics and eliminates the main obstacle of Mg2(Si,Sn) material integration in thermoelectric power generators.

High performance of Bi2Te3-based thermoelectric generator owing to pressure in fabrication process

A Bi2Te3-based thermoelectric generator (TEG) is known to be the leading technology in low-temperature heat energy recovery. In its fabricating process, the thermoelectric (TE) materials should be heated over the melting temperature of tin solder, but the unmatched thermal expansion between p-type and n-type TE materials will lead to considerable interfacial resistivity, resulting in the sharp decrease of the output power and conversion efficiency. Here, we introduce the pressure to suppress interfacial resistance of Bi2Te3-based TEGs. The theoretical model governing the pressure and interfacial resistivity is built based on the equations of thermal-electric-elastic coupling, and the explicit expressions for maximum output power and conversion efficiency are derived when considering interfacial resistivity. With the guidance of theoretical and simulation results, the average interfacial resistivity of 10 μΩ·cm2 is measured in a Bi2Te3-based TEG, while the conversion efficiency is increased by 44% from the commercial devices. Besides, the stress caused by suitable pressure force is less than the allowable stress of Bi2Te3-based TE materials. These findings provide strong support for the fabrication of high-performance TEGs.

Bonding Performance of Ag-Cu Brazing Solders and Half-Heusler Alloys for High-Performance Thermoelectric Generators.

Due to the uncertainty of the brazing solder composition and its unknown effect on the long-term stability of the interface, the brazing interface connection process for half-Heusler (hH) thermoelectric (TE) devices is still partially concealed and incomplete. In this work, we selected different types of Ag-Cu-based brazing solders with different Ag and Cu contents to assemble hH TE devices, observed the microstructure of the interface contact, and analyzed its formation mechanism. It is found that when the Cu element in the brazing solder is high, it tends to form an intermetallic compound (IMC) layer at the interface, which threatens the life of the device. On the contrary, when the content of the Ag element is high, the formation of the IMC layer will be avoided. Then, the long-term stability of the interface brazed by Ag72Cu28 with high Ag content was verified: the interface connection showed good contact resistivity stability and mechanical reliability; the fabricated uni-couple TE module achieved a maximum output power of 0.28 W and a maximum conversion efficiency of 7.34% at a temperature difference of 538 K. This work summarizes the selection principle of Cu-Ag-based brazing solder when assembling hH TE modules and verifies the long-term stability of the brazed connection interface. The experiment results can provide a reference for the actual fabrication of hH TE devices.

Analyzing and optimizing the power generation performance of thermoelectric generators based on an industrial environment

The industrial production process consumes electricity and generates a lot of waste heat. Recycling waste heat for power generation can effectively improve energy efficiency. This study uses thermoelectric conversion technology to recover industrial waste heat and designs a high-performance thermoelectric generator (TEG). According to the characteristics of industrial environmental temperature, the power generation performance of the TEG of various sizes is analyzed by a numerical calculation method. The TEG's structure, cooling method, and heat collection method are optimized based on numerical calculation results. After completing the structural optimization of the TEG, we conducted a field test of the equipment at a steel company in China. The results show that the optimized TEG has good power generation performance and can operate efficiently in an industrial environment. The best power generation performance can be obtained when the optimized TEG adopts the structure of 20cm × 150 cm. The maximum output power is 80.5 W, which is 11.2% higher than the unoptimized TEG. The best economic benefits can be obtained when the optimized TEG adopts the structure of 20cm × 75 cm. The minimum power generation cost is 1.76$W−1, which is 15.4% higher than the unoptimized TEG.

Elastic behavior of metal-assisted etched Si/SiGe superlattice nanowires containing dislocations

We systematically investigate structural parameters, such as shape, size, elastic strain, and relaxations, of metal-assisted etched vertically modulated Si/SiGe superlattice nanowires by using electron microscopy, synchrotron-based x-ray diffraction, and numerical linear elasticity theory. A vertical Si/Ge superlattice with atomically flat interfaces is grown by using molecular beam epitaxy on Si-buffered Si(001) substrates. The lattice constants for Si and Ge are 5.43 and 5.66 Å, respectively, which indicate a lattice mismatch of 4.2%. This results in a strained layer in the boundary between Si and Ge leading to dislocations. These substrates serve as the starting material for nanostructuring the surface by using metal-assisted etching. It is shown that the high quality crystalline structure is preserved in the fabrication process, while the lattice mismatch is partially relieved by dislocation formation. Despite this highly effective relaxation path, dislocations present in the parent superlattice do not vanish upon nanostructuring for wires with diameters of down to at least 80 nm. We relate these observations to the applicability of silicon-based nanowires for high-performance thermoelectric generators.

Defect Engineering Boosted Ultrahigh Thermoelectric Power Conversion Efficiency in Polycrystalline SnSe.

Two-dimensional (2D)-layered atomic arrangement with ultralow lattice thermal conductivity and ultrahigh figure of merit in single-crystalline SnSe drew significant attention among all thermoelectric materials. However, the processing of polycrystalline SnSe with equivalent thermoelectric performance as single-crystal SnSe will have great technological significance. Herein, we demonstrate a high zT of 2.4 at 800 K through the optimization of intrinsic defects in polycrystalline SnSe via controlled alpha irradiation. Through a detailed theoretical calculation of defect formation energies and lattice dynamic phonon dispersion studies, we demonstrate that the presence of intrinsically charged Sn vacancies can enhance the power factor and distort the lattice thermal conductivity by phonon-defect scattering. Supporting our theoretical calculations, the experimental enhancement in the electrical conductivity leads to a massive power factor of 0.9 mW/mK2 and an ultralow lattice thermal conductivity of 0.22 W/mK through the vacancy-phonon scattering effect on polycrystalline SnSe. The strategy of intrinsic defect engineering of polycrystalline thermoelectric materials can increase the practical implementation of low-cost and high-performance thermoelectric generators.

From carbon nanotubes to highly adaptive and flexible high-performance thermoelectric generators

Flexible thermoelectric generators (TEGs) provide a sustainable solution for directly harvesting low-grade heat from various curved surfaces, presenting a promising potential for feeding energy to personal-electronics or internet-of-things systems. Nevertheless, the room-temperature millivolt output of the cutting-edge all-solid-state flexible material-based TEGs (AF-TEGs) is still unappeasable for flexible electronics in practical applications. Here, we report on an AF-TEG consisting of a 3-level structure based on thin-film carbon nanotube (CNT) assemblies that can generate a high voltage (1.05 V) and sufficient outpower (0.95 mW) at moderate ΔT (~44 and 39 K, respectively) for powering an electrochromic device. The advanced nature of the AF-TEG is that conformation is highly adaptive and programmable, showing the surface suitability which can capture waste heat in both in-plane and out-of-plane direction. Moreover, an AF-TEG power management scheme is proposed for powering a commercial LED and an electronic thermometer, which indicate promising potential for practical applications.

All-Oxide p-n Junction Thermoelectric Generator Based on SnOx and ZnO Thin Films.

Achieving thermoelectric devices with high performance based on low-cost and nontoxic materials is extremely challenging. Moreover, as we move toward an Internet-of-Things society, a miniaturized local power source such as a thermoelectric generator (TEG) is desired to power increasing numbers of wireless sensors. Therefore, in this work, an all-oxide p-n junction TEG composed of low-cost, abundant, and nontoxic materials, such as n-type ZnO and p-type SnOx thin films, deposited on borosilicate glass substrate is proposed. A type II heterojunction between SnOx and ZnO films was predicted by density functional theory (DFT) calculations and confirmed experimentally by X-ray photoelectron spectroscopy (XPS). Moreover, scanning transmission electron microscopy (STEM) combined with energy-dispersive X-ray spectroscopy (EDS) show a sharp interface between the SnOx and ZnO layers, confirming the high quality of the p-n junction even after annealing at 523 K. ZnO and SnOx thin films exhibit Seebeck coefficients (α) of ∼121 and ∼258 μV/K, respectively, at 298 K, resulting in power factors (PF) of 180 μW/m K2 (for ZnO) and 37 μW/m K2 (for SnOx). Moreover, the thermal conductivities of ZnO and SnOx films are 8.7 and 1.24 W/m K, respectively, at 298 K, with no significant changes until 575 K. The four pairs all-oxide TEG generated a maximum power output (Pout) of 1.8 nW (≈126 μW/cm2) at a temperature difference of 160 K. The output voltage (Vout) and output current (Iout) at the maximum power output of the TEG are 124 mV and 0.0146 μA, respectively. This work paves the way for achieving a high-performance TEG device based on oxide thin films.