3 research outputs found
Thermoelectric properties of low-cost transparent single wall carbon nanotube thin films obtained by vacuum filtration
Π’Π΅ΠΊΡΡ ΡΡΠ°ΡΡΠΈ Π½Π΅ ΠΏΡΠ±Π»ΠΈΠΊΡΠ΅ΡΡΡ Π² ΠΎΡΠΊΡΡΡΠΎΠΌ Π΄ΠΎΡΡΡΠΏΠ΅ Π² ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΠΈΠΈ Ρ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΎΠΉ ΠΆΡΡΠ½Π°Π»Π°.The dispersions of semiconducting (sc-) and metallic (m-) SWCNTs with purity more than 98 and 86%, correspondingly,
were obtained by using the aqueous two-phase extraction method. The unseparated (un-) SWCNTs
contained ~3/4 of semiconducting and ~1/4 of metallic nanotubes. Thin films based on unseparated, semiconducting
and metallic SWCNTs were prepared by vacuum filtration method. An Atomic Force Microscopy
(AFM) and a Transmission Electronic Microscopy (TEM) were used to investigate the thin film microstructure.
The thin SWCNT film transmittance was measured in the wavelength range of 300β1500 nm. Thermoelectric
properties were carried out in the temperature range up to 200 Β°C. The largest Seebeck coefficient was observed
for thin films based on semiconducting SWCNTs. The maximum value was 98 ΞΌV/K under the temperature of
170 Β°C. The lowest resistivity was 7.5Β·10β4Β·OhmΒ·cm at room temperature for thin un-SWCNT films. The power
factor for m-SWCNT and un-SWCNT films was 47 and 213 ΞΌWmβ1 Kβ2, correspondingly, at room temperature
and 74 and 54 ΞΌWmβ1 Kβ2 at 200 Β°C, respectively. For a thin sc-SWCNT film the maximum power factor was
2.8 ΞΌWmβ1 Kβ2 at 160 Β°C. The un-SWCNT film thermal conductivity coefficient was 5.63 and 3.64Wmβ1 Kβ1
and a thermoelectric figure of merit was 0.011 and 0.016 at temperatures of 23 and 50 Β°C, respectively
Π’Π΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ½Π°Ρ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡ ΡΠΎΡΠΎΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΡΡΠΈ ΠΈ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΡΠΎΠ½ΠΊΠΈΡ ΠΏΠ»Π΅Π½ΠΎΠΊ In2O3, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ Π°Π²ΡΠΎΠ²ΠΎΠ»Π½ΠΎΠ²ΠΎΠ³ΠΎ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΡ
The influences of ultraviolet (UV) irradiation and temperature on the electrical and optical properties in
In2O3 films obtained by autowave oxidation were measured experimentally. The film resistance changed
slightly for temperatures from 300 to 95 K, and more noticeably when the temperature was further de-
creased, measured in the dark. Under UV irradiation, the resistivity of the films at room temperature
decreased sharply by 25% and from 300 to 95 K, and continued to decrease by 38% with a further
decreasing temperature. When the UV source was turned off, the resistivity relaxed at a rate of 15 Ξ©/s
for the first 30 seconds and 7 Ξ©/s for the remaining time. The transmittance decreased by 3.1% at
a wavelength of 6.3 m after the irradiation ceased. The velocity of the relaxation transmittance was
0.006 %/s. The relaxation of the electrical resistance and transmittance after UV irradiation termination
were similar. It was assumed that the dominant mechanism responsible for the change in the conductivity
in the indium oxide films during UV irradiation was photoreductionΠΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΡΠ»ΡΡΡΠ°ΡΠΈΠΎΠ»Π΅ΡΠΎΠ²ΠΎΠ³ΠΎ (Π£Π€) ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ ΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ Π½Π°
ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΠΏΠ»Π΅Π½ΠΎΠΊ In2O3, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ Π°Π²ΡΠΎΠ²ΠΎΠ»Π½ΠΎΠ²ΠΎΠ³ΠΎ ΠΎΠΊΠΈΡΠ»Π΅-
Π½ΠΈΡ. ΠΡΠΈ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΈ Π² ΡΠ΅ΠΌΠ½ΠΎΡΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΠ΅ ΠΏΠ»Π΅Π½ΠΊΠΈ ΠΌΠ΅Π½ΡΠ»ΠΎΡΡ Π½Π΅Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎ ΠΏΡΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡ-
ΡΠ°Ρ
ΠΎΡ 300 Π΄ΠΎ 95 Π ΠΈ Π±ΠΎΠ»Π΅Π΅ Π·Π°ΠΌΠ΅ΡΠ½ΠΎ ΠΏΡΠΈ Π΄Π°Π»ΡΠ½Π΅ΠΉΡΠ΅ΠΌ ΡΠΌΠ΅Π½ΡΡΠ΅Π½ΠΈΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ. ΠΠΎΠ΄ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ
Π£Π€βΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ ΡΠ΄Π΅Π»ΡΠ½ΠΎΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΠ΅ ΠΏΠ»Π΅Π½ΠΎΠΊ ΠΏΡΠΈ ΠΊΠΎΠΌΠ½Π°ΡΠ½ΠΎΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ ΡΠ΅Π·ΠΊΠΎ ΡΠ½ΠΈΠ·ΠΈΠ»ΠΎΡΡ Π½Π°
25 %, ΠΎΡ 300 Π΄ΠΎ 95 Π, ΠΈ ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠ°Π»ΠΎ ΡΠ½ΠΈΠΆΠ°ΡΡΡΡ Π΄ΠΎ 38% Ρ Π΄Π°Π»ΡΠ½Π΅ΠΉΡΠΈΠΌ ΠΏΠΎΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ΠΌ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°-
ΡΡΡΡ. ΠΡΠΈ ΠΎΡΠΊΠ»ΡΡΠ΅Π½ΠΈΠΈ Π£Π€βΠΈΡΡΠΎΡΠ½ΠΈΠΊΠ° Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΡ ΡΠ΅Π»Π°ΠΊΡΠΈΡΠΎΠ²Π°Π»ΠΎ ΡΠΎ ΡΠΊΠΎΡΠΎΡΡΡΡ 15
ΠΠΌ/Ρ Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΏΠ΅ΡΠ²ΡΡ
30 ΡΠ΅ΠΊΡΠ½Π΄ ΠΈ 7 ΠΠΌ/Ρ Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΎΡΡΠ°Π²ΡΠ΅Π³ΠΎΡΡ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ. ΠΠΎΡΠ»Π΅ ΠΏΡΠ΅ΠΊΡΠ°ΡΠ΅Π½ΠΈΡ
ΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½Ρ ΠΏΡΠΎΠΏΡΡΠΊΠ°Π½ΠΈΡ ΡΠ½ΠΈΠ·ΠΈΠ»ΡΡ Π½Π° 3,1% ΠΏΡΠΈ Π΄Π»ΠΈΠ½Π΅ Π²ΠΎΠ»Π½Ρ 6,3 ΠΌΠΊΠΌ. Π‘ΠΊΠΎΡΠΎΡΡΡ ΡΠ΅-
Π»Π°ΠΊΡΠ°ΡΠΈΠΈ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΏΡΠΎΠΏΡΡΠΊΠ°Π½ΠΈΡ ΡΠΎΡΡΠ°Π²ΠΈΠ»Π° 0,006 %/Ρ. Π Π΅Π»Π°ΠΊΡΠ°ΡΠΈΠΈ ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΠΏΡΠΎΡΠΈΠ²-
Π»Π΅Π½ΠΈΡ ΠΈ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΏΡΠΎΠΏΡΡΠΊΠ°Π½ΠΈΡ ΠΏΠΎΡΠ»Π΅ ΠΏΡΠ΅ΠΊΡΠ°ΡΠ΅Π½ΠΈΡ Π£Π€βΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ Π±ΡΠ»ΠΈ ΠΎΠ΄ΠΈΠ½Π°ΠΊΠΎΠ²ΡΠΌΠΈ. ΠΡΠ΅Π΄-
ΠΏΠΎΠ»Π°Π³Π°Π΅ΡΡΡ, ΡΡΠΎ Π΄ΠΎΠΌΠΈΠ½ΠΈΡΡΡΡΠΈΠΌ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠΌ, ΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΡΠΌ Π·Π° ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΡΡΠΈ Π²
ΠΏΠ»Π΅Π½ΠΊΠ°Ρ
ΠΎΠΊΡΠΈΠ΄Π° ΠΈΠ½Π΄ΠΈΡ Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ Π£Π€-ΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ, Π±ΡΠ»ΠΎ ΡΠΎΡΠΎΠ²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈ
Π’Π΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ½Π°Ρ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΡ ΡΠΎΡΠΎΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΡΡΠΈ ΠΈ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΡΠΎΠ½ΠΊΠΈΡ ΠΏΠ»Π΅Π½ΠΎΠΊ In2O3, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ Π°Π²ΡΠΎΠ²ΠΎΠ»Π½ΠΎΠ²ΠΎΠ³ΠΎ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΡ
The influences of ultraviolet (UV) irradiation and temperature on the electrical and optical properties in
In2O3 films obtained by autowave oxidation were measured experimentally. The film resistance changed
slightly for temperatures from 300 to 95 K, and more noticeably when the temperature was further de-
creased, measured in the dark. Under UV irradiation, the resistivity of the films at room temperature
decreased sharply by 25% and from 300 to 95 K, and continued to decrease by 38% with a further
decreasing temperature. When the UV source was turned off, the resistivity relaxed at a rate of 15 Ξ©/s
for the first 30 seconds and 7 Ξ©/s for the remaining time. The transmittance decreased by 3.1% at
a wavelength of 6.3 m after the irradiation ceased. The velocity of the relaxation transmittance was
0.006 %/s. The relaxation of the electrical resistance and transmittance after UV irradiation termination
were similar. It was assumed that the dominant mechanism responsible for the change in the conductivity
in the indium oxide films during UV irradiation was photoreductionΠΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΡΠ»ΡΡΡΠ°ΡΠΈΠΎΠ»Π΅ΡΠΎΠ²ΠΎΠ³ΠΎ (Π£Π€) ΠΈΠ·Π»ΡΡΠ΅Π½ΠΈΡ ΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ Π½Π°
ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΠΏΠ»Π΅Π½ΠΎΠΊ In2O3, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ Π°Π²ΡΠΎΠ²ΠΎΠ»Π½ΠΎΠ²ΠΎΠ³ΠΎ ΠΎΠΊΠΈΡΠ»Π΅-
Π½ΠΈΡ. ΠΡΠΈ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΈ Π² ΡΠ΅ΠΌΠ½ΠΎΡΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΠ΅ ΠΏΠ»Π΅Π½ΠΊΠΈ ΠΌΠ΅Π½ΡΠ»ΠΎΡΡ Π½Π΅Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎ ΠΏΡΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡ-
ΡΠ°Ρ
ΠΎΡ 300 Π΄ΠΎ 95 Π ΠΈ Π±ΠΎΠ»Π΅Π΅ Π·Π°ΠΌΠ΅ΡΠ½ΠΎ ΠΏΡΠΈ Π΄Π°Π»ΡΠ½Π΅ΠΉΡΠ΅ΠΌ ΡΠΌΠ΅Π½ΡΡΠ΅Π½ΠΈΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΡ. ΠΠΎΠ΄ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ
Π£Π€βΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ ΡΠ΄Π΅Π»ΡΠ½ΠΎΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΠ΅ ΠΏΠ»Π΅Π½ΠΎΠΊ ΠΏΡΠΈ ΠΊΠΎΠΌΠ½Π°ΡΠ½ΠΎΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ ΡΠ΅Π·ΠΊΠΎ ΡΠ½ΠΈΠ·ΠΈΠ»ΠΎΡΡ Π½Π°
25 %, ΠΎΡ 300 Π΄ΠΎ 95 Π, ΠΈ ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠ°Π»ΠΎ ΡΠ½ΠΈΠΆΠ°ΡΡΡΡ Π΄ΠΎ 38% Ρ Π΄Π°Π»ΡΠ½Π΅ΠΉΡΠΈΠΌ ΠΏΠΎΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ΠΌ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°-
ΡΡΡΡ. ΠΡΠΈ ΠΎΡΠΊΠ»ΡΡΠ΅Π½ΠΈΠΈ Π£Π€βΠΈΡΡΠΎΡΠ½ΠΈΠΊΠ° Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ ΡΠΎΠΏΡΠΎΡΠΈΠ²Π»Π΅Π½ΠΈΡ ΡΠ΅Π»Π°ΠΊΡΠΈΡΠΎΠ²Π°Π»ΠΎ ΡΠΎ ΡΠΊΠΎΡΠΎΡΡΡΡ 15
ΠΠΌ/Ρ Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΏΠ΅ΡΠ²ΡΡ
30 ΡΠ΅ΠΊΡΠ½Π΄ ΠΈ 7 ΠΠΌ/Ρ Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΎΡΡΠ°Π²ΡΠ΅Π³ΠΎΡΡ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ. ΠΠΎΡΠ»Π΅ ΠΏΡΠ΅ΠΊΡΠ°ΡΠ΅Π½ΠΈΡ
ΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½Ρ ΠΏΡΠΎΠΏΡΡΠΊΠ°Π½ΠΈΡ ΡΠ½ΠΈΠ·ΠΈΠ»ΡΡ Π½Π° 3,1% ΠΏΡΠΈ Π΄Π»ΠΈΠ½Π΅ Π²ΠΎΠ»Π½Ρ 6,3 ΠΌΠΊΠΌ. Π‘ΠΊΠΎΡΠΎΡΡΡ ΡΠ΅-
Π»Π°ΠΊΡΠ°ΡΠΈΠΈ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΏΡΠΎΠΏΡΡΠΊΠ°Π½ΠΈΡ ΡΠΎΡΡΠ°Π²ΠΈΠ»Π° 0,006 %/Ρ. Π Π΅Π»Π°ΠΊΡΠ°ΡΠΈΠΈ ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΠΏΡΠΎΡΠΈΠ²-
Π»Π΅Π½ΠΈΡ ΠΈ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΏΡΠΎΠΏΡΡΠΊΠ°Π½ΠΈΡ ΠΏΠΎΡΠ»Π΅ ΠΏΡΠ΅ΠΊΡΠ°ΡΠ΅Π½ΠΈΡ Π£Π€βΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ Π±ΡΠ»ΠΈ ΠΎΠ΄ΠΈΠ½Π°ΠΊΠΎΠ²ΡΠΌΠΈ. ΠΡΠ΅Π΄-
ΠΏΠΎΠ»Π°Π³Π°Π΅ΡΡΡ, ΡΡΠΎ Π΄ΠΎΠΌΠΈΠ½ΠΈΡΡΡΡΠΈΠΌ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠΌ, ΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΡΠΌ Π·Π° ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠΌΠΎΡΡΠΈ Π²
ΠΏΠ»Π΅Π½ΠΊΠ°Ρ
ΠΎΠΊΡΠΈΠ΄Π° ΠΈΠ½Π΄ΠΈΡ Π² ΠΏΡΠΎΡΠ΅ΡΡΠ΅ Π£Π€-ΠΎΠ±Π»ΡΡΠ΅Π½ΠΈΡ, Π±ΡΠ»ΠΎ ΡΠΎΡΠΎΠ²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈ