Atomic composition changes in bismuth telluride thin films by thermal annealing and estimation of their thermoelectric properties using experimental analyses and first-principles calculations

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

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First-principles calculations to investigate mechanical, optoelectronic and thermoelectric properties of half-Heusler p-type semiconductor BaAgP

Results in Physics ◽

10.1016/j.rinp.2021.104068 ◽

2021 ◽

pp. 104068

Author(s):

F. Parvin ◽

M.A. Hossain ◽

I. Ahmed ◽

K. Akter ◽

A.K.M.A. Islam

Keyword(s):

Thermoelectric Properties ◽

First Principles ◽

First Principles Calculations ◽

Type Semiconductor ◽

P Type

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Effects of RF Magnetron Sputtering Deposition Power on Crystallinity and Thermoelectric Properties of Antimony Telluride and Bismuth Telluride Thin Films on Flexible Substrates

Journal of Electronic Materials ◽

10.1007/s11664-020-08681-y ◽

2021 ◽

Author(s):

Farbod Amirghasemi ◽

Sam Kassegne

Keyword(s):

Thin Films ◽

Magnetron Sputtering ◽

Thermoelectric Properties ◽

Bismuth Telluride ◽

Rf Magnetron Sputtering ◽

Flexible Substrates ◽

Antimony Telluride ◽

Sputtering Deposition ◽

Deposition Power

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Direct measurement of the thermoelectric properties of electrochemically deposited Bi2Te3 thin films

Scientific Reports ◽

10.1038/s41598-020-74887-z ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jose Recatala-Gomez ◽

Pawan Kumar ◽

Ady Suwardi ◽

Anas Abutaha ◽

Iris Nandhakumar ◽

...

Keyword(s):

Thin Films ◽

Thermoelectric Properties ◽

Bismuth Telluride ◽

Indium Tin Oxide ◽

Seed Layer ◽

Room Temperature ◽

Low Cost ◽

Temperature Dependent ◽

Temperature Heat ◽

Electrochemically Deposited

Abstract The best known thermoelectric material for near room temperature heat-to-electricity conversion is bismuth telluride. Amongst the possible fabrication techniques, electrodeposition has attracted attention due to its simplicity and low cost. However, the measurement of the thermoelectric properties of electrodeposited films is challenging because of the conducting seed layer underneath the film. Here, we develop a method to directly measure the thermoelectric properties of electrodeposited bismuth telluride thin films, grown on indium tin oxide. Using this technique, the temperature dependent thermoelectric properties (Seebeck coefficient and electrical conductivity) of electrodeposited thin films have been measured down to 100 K. A parallel resistor model is employed to discern the signal of the film from the signal of the seed layer and the data are carefully analysed and contextualized with literature. Our analysis demonstrates that the thermoelectric properties of electrodeposited films can be accurately evaluated without inflicting any damage to the films.

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