High thermopower in (00l)-Oriented nanocrystalline Bi-Sb-Te thin films produced by one-step thermal evaporation process

Vacuum ◽  
2019 ◽  
Vol 165 ◽  
pp. 12-18 ◽  
Author(s):  
Sukhdeep Singh ◽  
Janpreet Singh ◽  
S.K. Tripathi
Author(s):  
G. G. Paulson ◽  
R. E. Ferrell

In such fields as electronics and optics, the sputtering process is rapidly displacing the conventional evaporation process. Its major advantage is the ability to deposit a variety of refractory metals and dielectric materials with good control and reproducibility. This advantage and numerous others are valid reasons why sputtering may eventually displace thermal evaporation in the typical electron microscope laboratory. Sputtering is readily adapted to the procedures utilized in TEM, however, the following discussion highlights the advantages of sputtering for applying coatings to specimens for SEM.Sputtering is not a new concept. Numerous papers and books had been published before 1900 concerning the use of sputtering for depositing thin films.


CrystEngComm ◽  
2012 ◽  
Vol 14 (13) ◽  
pp. 4298 ◽  
Author(s):  
Zai-Xing Yang ◽  
Peng Zhang ◽  
Wei Zhong ◽  
Yu Deng ◽  
Chak-Tong Au ◽  
...  

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.


2016 ◽  
Vol 12 (3) ◽  
pp. 4394-4399
Author(s):  
Sura Ali Noaman ◽  
Rashid Owaid Kadhim ◽  
Saleem Azara Hussain

Tin Oxide and Indium doped Tin Oxide (SnO2:In) thin films were deposited on glass and Silicon  substrates  by  thermal evaporation technique.  X-ray diffraction pattern of  pure SnO2 and SnO2:In thin films annealed at 650oC and the results showed  that the structure have tetragonal phase with preferred orientation in (110) plane. AFM studies showed an inhibition of grain growth with increase in indium concentration. SEM studies of pure  SnO2 and  Indium doped tin oxide (SnO2:In) ) thin films showed that the films with regular distribution of particles and they have spherical shape.  Optical properties such as  Transmission , optical band-gap have been measured and calculated.


2018 ◽  
Vol 1 (1) ◽  
pp. 21-25
Author(s):  
R Revathi ◽  
R Karunathan

Indium Telluride thin films were prepared by thermal evaporation technique. Films were annealed at 573K under vacuum for an hour. Both as-deposited and annealed films were used for characterization. The structural parameters were discussed on the basis of annealing effect for a film of thickness 1500 Å. Optical analysis was carried out on films of different thicknesses for both as - deposited and annealed samples. Both the as- deposited and annealed films exhibit direct and allowed transition. Electrical resistivity measurements were made in the temperature range of 303-473 K using Four-probe method. The calculated resistivity value is of the order of 10-6 ohm meter. The activation energy value decreases with increasing film thickness. The negative temperature coefficient indicates the semiconducting nature of the film.


2019 ◽  
Vol 15 (34) ◽  
pp. 1-14
Author(s):  
Bushra A. Hasan

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.


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