scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Cheng-Fu Yang ◽  
Wei Chen

The antimony-telluride (Sb2Te3) thermoelectric thin films were prepared on SiO2/Si substrates by thermal evaporation method. The substrate temperature that ranged from room temperature to 150°C was adopted to deposit the Sb2Te3thin films. The effects of substrate temperature on the microstructures and thermoelectric properties of the Sb2Te3thin films were investigated. The crystal structure and surface morphology of the Sb2Te3thin films were characterized by X-ray diffraction analyses and field emission scanning electron microscope observation. The RT-deposited Sb2Te3thin films showed the amorphous phase. Te and Sb2Te3phases were coexisted in the Sb2Te3-based thin films as the substrate temperature was higher than room temperature. The average grain sizes of the Sb2Te3-based thin films were 39 nm, 45 nm, 62 nm, 84 nm, and 108 nm, as the substrate temperatures were 50°C, 75°C, 100°C, 125°C, and 150°C, respectively. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature; we had found that they were critically dependent on the substrate temperature.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Wei Chen

Thermoelectric (TE) materials are crucial because they can be used in power generation and cooling devices. Sb2Te3-based compounds are the most favorable TE materials because of their excellent figure of merit at room temperature. In this study, Sb2Te3thin films were prepared on SiO2/Si substrates through thermal evaporation. The influence of the evaporation current on the microstructures and TE properties of Sb2Te3thin films were investigated. The crystalline structures and morphologies of the thin films were analyzed using X-ray diffraction and field emission scanning electron microscopy. The Seebeck coefficient, electrical conductivity, and power factor (PF) were measured at room temperature. The experimental results showed that the Seebeck coefficient increased and conductivity decreased with increasing evaporation current. The Seebeck coefficient reached a maximum of 387.58 μV/K at an evaporation current of 80 A. Conversely, a PF of 3.57 µW/cmK2was obtained at room temperature with evaporation current of 60 A.


2014 ◽  
Vol 879 ◽  
pp. 175-179 ◽  
Author(s):  
Safaa I. Mohammed ◽  
Naser Mahmoud Ahmed ◽  
Y. Al-Douri ◽  
U. Hashim

Lead iodide (PbI2) thin films were successfully prepared by thermal evaporation method on a glass substrate at room temperature. The structural analysis of these films was done by XRD. The results revealed that the crystallite size increases when increasing the film thickness and annealing temperature. In addition, the preferred growth orientation was 001 for all the samples.


2012 ◽  
Vol 538-541 ◽  
pp. 154-157
Author(s):  
Peng Juan Liu ◽  
Ping Fan ◽  
Zhuang Hao Zheng ◽  
Dong Ping Zhang ◽  
Xing Min Cai ◽  
...  

Antimony (Sb) and zinc (Zn) bilayer was sputter-deposited at room temperature with various Zn contents by ion-beam sputtering and transformed into Antimony zinc after post thermal annealed at 573K for 60 min. A power factor of 6.18×10-4 W/mK2 at 473 K has been obtained when the sputtering time of the Zn was 20 minutes. The maximum Seebeck coefficient is 42.0 μVK-1. Composition analysis shows that the compound of SbZn is achieved and the small Seebeck coefficient is due to the deviation of stoichiometric.


2020 ◽  
Vol 46 (16) ◽  
pp. 25992-25995
Author(s):  
Hassnain Zaman ◽  
Jolly Jacob ◽  
Khurram Mehboob ◽  
K. Mahmood ◽  
U. Rehman ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Sarita Boolchandani ◽  
Subodh Srivastava ◽  
Y. K. Vijay

The indium selenium (InSe) bilayer thin films of various thickness ratios, InxSe(1-x) (x = 0.25, 0.50, 0.75), were deposited on a glass substrate keeping overall the same thickness of 2500 Ǻ using thermal evaporation method under high vacuum atmosphere. Electrical, optical, and structural properties of these bilayer thin films have been compared before and after thermal annealing at different temperatures. The structural and morphological characterization was done using XRD and SEM, respectively. The optical bandgap of these thin films has been calculated by Tauc’s relation that varies within the range of 1.99 to 2.05 eV. A simple low-cost thermoelectrical power measurement setup is designed which can measure the Seebeck coefficient “S” in the vacuum with temperature variation. The setup temperature variation is up to 70°C. This setup contains a Peltier device TEC1-12715 which is kept between two copper plates that act as a reference metal. Also, in the present work, the thermoelectric power of indium selenide (InSe) and aluminum selenide (AlSe) bilayer thin films prepared and annealed in the same way is calculated. The thermoelectric power has been measured by estimating the Seebeck coefficient for InSe and AlSe bilayer thin films. It was observed that the Seebeck coefficient is negative for InSe and AlSe thin films.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Faheem Amin ◽  
Syedah Afsheen Zahra ◽  
Muhammad Sultan ◽  
Sajjad Hussain Mirza ◽  
Fahad Azad

Bilayer thin films of Ge/CdS have been deposited on a glass substrate through thermal evaporation method. The obtained Ge/CdS samples were annealed at temperatures up to 400°C to observe the resulting effect on the structural changes in the film. The bandgap of the annealed films was found to increase with increasing annealing temperature which can be attributed to the increased interlayer diffusion. The interlayer diffusion was found to take effect above a temperature of 300°C which was confirmed by the Rutherford backscattering technique. Complementary XPS was done to investigate the surface stoichiometry of the bilayers.


2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Swati Arora ◽  
Vivek Jaimini ◽  
Subodh Srivastava ◽  
Y. K. Vijay

Bismuth telluride has high thermoelectric performance at room temperature; in present work, various nanostructure thin films of bismuth telluride were fabricated on silicon substrates at room temperature using thermal evaporation method. Tellurium (Te) and bismuth (Bi) were deposited on silicon substrate in different ratio of thickness. These films were annealed at 50°C and 100°C. After heat treatment, the thin films attained the semiconductor nature. Samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to show granular growth.


2012 ◽  
Vol 26 (31) ◽  
pp. 1250137 ◽  
Author(s):  
M. AMIRHOSEINY ◽  
Z. HASSAN ◽  
S. S. NG ◽  
L. S. CHUAH ◽  
M. A. AHMAD ◽  
...  

We have fabricated photoconductors of indium nitride (InN) grown by radio frequency (RF) sputtering. The InN thin films were deposited on Si (100), Si (110) and Si (111) substrates at room temperature. The Ag/Al contact has been deposited by thermal evaporation in vacuum (10-5 Torr ) and then annealed under the flowing of the nitrogen gas environment in order to relieve stress and also induce any favorable reactions between metals and the semiconductor. Current–voltage (I–V) measurements after heat treatment at 400°C were carried out for samples in dark and illumination conditions. It was found that Ag/Al formed a good ohmic contact on top of InN . In addition, the characteristics of the contacts were significantly affected by the orientation of substrates.


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