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Advances in flexible telluride thin-film thermoelectric generators: Deposition, performance, and module fabrication
(2026-04-01)
Theekhasuk, Nattharika
;
Sakdanuphab, Rachsak
;
Kianwimol, Supasak
;
Khumtong, Thanakorn
;
Toan, Nguyen Van
Flexible thermoelectric generators (TEGs) are gaining increasing attention for wearable and skin-attachable electronics due to their ability to harvest low-grade heat from the human body. In this work, p-type Sb<inf>2</inf>Te<inf>3</inf> and n-type Bi<inf>2</inf>Te<inf>3</inf> thin films were deposited by direct current (DC) magnetron sputtering, and the effects of post-deposition annealing on their structural, electrical, and thermal transport properties were systematically evaluated. X-ray diffraction revealed that n-Bi<inf>2</inf>Te<inf>3</inf> exhibited higher crystallinity than p-Sb<inf>2</inf>Te<inf>3</inf>, attributed to its lower formation energy. Annealing at 250 °C markedly enhanced the electrical conductivity of both films, with p-Sb<inf>2</inf>Te<inf>3</inf> showing a larger improvement due to concurrent increases in carrier concentration and mobility driven by Te volatilization and the formation of acceptor-type vacancies and antisite defects. In contrast, n-Bi<inf>2</inf>Te<inf>3</inf> exhibited a slight reduction in carrier concentration as a result of compensating donor defects. Consequently, maximum ZT values of approximately 0.5 for p-Sb<inf>2</inf>Te<inf>3</inf> and 0.25 for n-Bi<inf>2</inf>Te<inf>3</inf> were achieved at 513 K. Notably, the compatibility factor (S) values of both films differed by less than a factor of two, indicating favorable thermodynamic pairing for p–n module assembly. A flexible TEG module with 12 thermocouples was subsequently fabricated and delivered an output power of 0.65 μW at ΔT < 25 K, demonstrating promising potential for scalable self-powered wearable electronics.
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Improvement structure and electrical properties of ITO thin films by annealing treatment
(2024-01-01)
Srithanachai, I.
;
Sangwaranatee, N.
In this paper present, the improvement of ITO thin films properties by thermal annealing treatment by various temperature. The process for this investigation various temperature 100-500 ◦C under nitrogen environment, control time for 23 mins. The films crystallization improves after annealing process by XRD results show strong peak after post-annealing and resistivity of thin films shows significant reduced from 1996 to 706 O-cm. The films crystallization shows small peak after thin film growth, however treatment process induced strong peak (222) and (441). The optimization point of treatment process can improve thin films properties that can apply thin films for low energy photodiode.
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Effect of annealing temperature on thermoelectric properties of bismuth telluride thick film deposited by DC magnetron sputtering
(2020-07-15)
Kianwimol, Supasak
;
Sakdanuphab, Rachsak
;
Chanlek, Narong
;
Harnwunggmoung, Adul
;
Sakulkalavek, Aparporn
We report the thermoelectric properties of thick bismuth-telluride (Bi<inf>2</inf>Te<inf>3</inf>) films deposited on polyimide substrates by DC magnetron sputtering and annealed at various temperatures (150–350 °C). The influence of annealing temperature on the microstructure and electronic structure of thick Bi<inf>2</inf>Te<inf>3</inf> films is discussed. In this work, the annealed film at 250 °C has the best thermoelectric property due to highest electrical conductivity and Seebeck coefficient. The main effect of annealing temperature was really helpful to improve crystalline structure and enhance carrier mobility, whereas the carrier concentration was reduced due to the volatile of tellurium atom during annealing. Chemical states of bound and unbound atoms (Bi, Bi3+, Te, and Te2‐) on the surface play an important role in electrical properties. The exceed temperature caused the micro-crack formation and affect carrier transport by the scattering. The power factor of Bi<inf>2</inf>Te<inf>3</inf> deposited by DC magnetron sputtering and annealed at 250 °C is comparable to the power factors of thick Bi<inf>2</inf>Te<inf>3</inf> film deposited by various deposition techniques. The output power of single-leg, thick, thermoelectric Bi<inf>2</inf>Te<inf>3</inf> film annealed at 250 °C as a function temperature generated a power of 0.98 μW at a temperature difference of 50 °C.
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Comparative study of non-annealing and annealing on properties of ITO deposited by RF magnetron sputtering
(2015-01-01)
Khlayboonme, S. Tipawan
;
Warawoot, Thowladda
A comparison of the properties for two ITO thin films was performed. The two films were as follows - as-deposited and annealed ITO films. The influence of annealing on the structural, morphological, electrical, and optical properties was studied. The post-annealing treatment was done at a temperature of 400 for 1 h in air. The ITO thin films were deposited onto glass substrates by RF magnetron sputtering of a ceramic In<inf>2</inf>O<inf>3</inf>: SnO<inf>2</inf> target in pure argon atmosphere at a low base pressure of <10-6 mbar and a RF power of 50 W. The films were characterized by XRD, FTIR, contact angle measurements, FE-SEM combined with EDX, Halleffect measurements and UV-Vis transmission spectroscopy. The ITO films showed a crystalline structure with a predominant orientation (400) and its intensity was increased after the film was annealed. The structure of the annealed film became reformed in more perfect columnar structure. The annealed film showed a decrease in contact angle and increase in FTIR spectra intensity. The annealing induced more tin incorporated into the film from 0.51 to 2.62 at%. The resistivity decreased from 2.7×10-3 to 1.1×10-3 Ω cm with increasing mobility from 7.5 to 27.5 cm2 V-1 s-1 but decreasing carrier concentration from 3.0×1020 to 2.0 × 1020 cm-3. The optical band gap increased from 3.43 to 3.50 eV. All films showed highly transparency (×85%) in the visible light region. Compared with the non-annealed ITO film, the air-annealed ITO film revealed the better properties except for carrier concentration.
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