Efficient p-n junction-based thermoelectric generator that can operate at extreme temperature conditions

Chavez, Ruben; Angst, Sebastian; Hall, Joseph E.; Maculewicz, Franziska; Stoetzel, J.; Wiggers, Hartmut; Hưng, Lê Thành; Nong, Ngo Van; Pryds, Nini; Span, G.; Wolf, Dietrich E.; Schmechel, Roland; Schierning, Gabi

doi:10.1088/1361-6463/aa9b6a

Cited by 23 publications

(15 citation statements)

References 28 publications

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“…The activation energy of 1.1 ± 0.2 eV for the parallel shunt resistance Rp is much smaller than that of the saturation current density j0, which was attributed to minority carrier diffusion and with an activation energy intermediate of the band gaps of the two materials (Eg,av = 3.5 eV). We thus suggest that Rp may be related to mid-gap defect levels in the p-n-junction, as also suggested by Chavez et al for Si-based junctions [34].…”

Section: Resultssupporting

confidence: 85%

Electrical Properties of a p–n Heterojunction of Li-Doped NiO and Al-Doped ZnO for Thermoelectrics

Desissa

Schrade

Norby

2018

Journal of Elec Materi

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The electrical properties of a p-n heterojunction of polycrystalline p-type Ni0.98Li0.02O and n-type Zn0.98Al0.02O have been investigated for potential applications in high-temperature oxide-based thermoelectric generators without metallic interconnects. Current-voltage characteristics of the junction were measured in a two-electrode setup in ambient air at 500 -1000 °C. The resistance and rectification of the junction decreased with increasing temperature. A non-ideal Shockley diode model was used to fit the measured current-voltage data in order to extract characteristic parameters of the junction, such as areaspecific series resistance Rs and parallel shunt resistance Rp, non-ideality factor, and the saturation current density. Rs and Rp decreased exponentially with temperature, with activation energies of 0.4 ± 0.1 eV and 1.1 ± 0.2 eV, respectively. The interface resistance of the direct p-n junction studied here is as such too high for practical applications in thermoelectrics. However, it is demonstrated that it can be reduced by order of magnitude by using a composite of the individual materials at the interface, yielding a large effective contact area.

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Section: Resultssupporting

confidence: 85%

Electrical Properties of a p–n Heterojunction of Li-Doped NiO and Al-Doped ZnO for Thermoelectrics

Desissa

Schrade

Norby

2018

Journal of Elec Materi

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“…Figure b shows the replot of the J – V curve in the semilogarithmic mode for the heterojunctions, and the ideality factor is found to be ≈1.1. Since the ideality factor is close to unity, the electrical transport of the junctions is dominated by diffusion current, where recombination processes are minor. , Furthermore, the diode characteristics of the present device are improved when compared with the ones presented by Chavez et al , and Desissa et al in their bulk devices with a p–n junction without metal contact. Particularly, Chavez et al reported an inhomogeneous p–n junction due to the mixing of the nanoparticle powders prior to and during the densification step for the device fabrication.…”

Section: Results and Discussionmentioning

confidence: 53%

High-Performance μ-Thermoelectric Device Based on Bi₂Te₃/Sb₂Te₃ p–n Junctions

Vieira

Pires

Silva

et al. 2019

ACS Appl. Mater. Interfaces

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A flexible and ultralight planar thermoelectric generator based on 15 thermocouples composed of n-type bismuth telluride (Bi2Te3) and p-type antimony telluride (Sb2Te3) legs (each with 400 nm thick) connected in series, on 25 μm thick Kapton substrate, was fabricated with impressive power factor values of 2.7 and 0.8 mW K–2 m–1 (at 298 K) for Bi2Te3 and Sb2Te3 films, respectively. The p–n junction thermoelectric device can generate a maximum open-circuit voltage and output power of 210 mV and 0.7 μW (3.3 mW cm–2), respectively, for a temperature difference of 35 K, which is higher than the one observed for a conventional thermoelectric device with metallic contacts for p–n junctions. The results were combined with numerical simulations, showing a good match between the experimental and the numerical results. The current density versus voltage (J–V) characteristics of the fabricated p–n junctions revealed a diode behavior with a turn-on voltage of ≈0.3 V and an impressive rectifying ratio (I +1V/I –1V) of ≈2 × 104.

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“…Many of these issues could be tackled by the approach of Shin et al. through the use of oxide TEs with a direct p–n junction, hereby omitting the metal interconnects at the hot side. − However, p–n junctions are usually not Ohmic but exhibit rectifying behavior, which represent large parasitic resistances in the device. A solution to the rectifying behavior is a broken-gap junction couple, well-known in the field of photovoltaics. − A broken-gap junction forms a charge accumulation region instead of a charge depletion zone, which leads to fully Ohmic characteristics.…”

Section: Introductionmentioning

confidence: 99%

Near-Broken-Gap Alignment between FeWO₄and Fe₂WO₆for Ohmic Direct p–n Junction Thermoelectrics

Schuler

Bianchini

Norby

et al. 2021

ACS Appl. Mater. Interfaces

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We report a near-broken-gap alignment between p-type FeWO 4 and n-type Fe 2 WO 6 , a model pair for the realization of Ohmic direct junction thermoelectrics. Both undoped materials have a large Seebeck coefficient and high electrical conductivity at elevated temperatures, due to inherent electronic defects. A band-alignment diagram is proposed based on X-ray photoelectron and ultraviolet–visible light reflectance spectroscopy. Experimentally acquired nonrectifying I – V characteristics and the constructed band-alignment diagram support the proposed formation of a near-broken-gap junction. We have additionally performed computational modeling based on density functional theory (DFT) on bulk models of the individual compounds to rationalize the experimental band-alignment diagram and to provide deeper insight into the relevant band characteristics. The DFT calculations confirm an Fe-3d character of the involved band edges, which we suggest is a decisive feature for the unusual band overlap.

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Efficient p-n junction-based thermoelectric generator that can operate at extreme temperature conditions

Cited by 23 publications

References 28 publications

Electrical Properties of a p–n Heterojunction of Li-Doped NiO and Al-Doped ZnO for Thermoelectrics

Electrical Properties of a p–n Heterojunction of Li-Doped NiO and Al-Doped ZnO for Thermoelectrics

High-Performance μ-Thermoelectric Device Based on Bi₂Te₃/Sb₂Te₃ p–n Junctions

Near-Broken-Gap Alignment between FeWO₄and Fe₂WO₆for Ohmic Direct p–n Junction Thermoelectrics

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Efficient p-n junction-based thermoelectric generator that can operate at extreme temperature conditions

Cited by 23 publications

References 28 publications

Electrical Properties of a p–n Heterojunction of Li-Doped NiO and Al-Doped ZnO for Thermoelectrics

Electrical Properties of a p–n Heterojunction of Li-Doped NiO and Al-Doped ZnO for Thermoelectrics

High-Performance μ-Thermoelectric Device Based on Bi2Te3/Sb2Te3 p–n Junctions

Near-Broken-Gap Alignment between FeWO4and Fe2WO6for Ohmic Direct p–n Junction Thermoelectrics

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Product

Resources

About

High-Performance μ-Thermoelectric Device Based on Bi₂Te₃/Sb₂Te₃ p–n Junctions

Near-Broken-Gap Alignment between FeWO₄and Fe₂WO₆for Ohmic Direct p–n Junction Thermoelectrics