Modulated carrier concentration and enhanced seebeck coefficient of Ge2Sb2Te5 thin films by Sn doping

Vacuum ◽  
2022 ◽  
pp. 110881
Author(s):  
Jiale Miao ◽  
Dongjie Qian ◽  
Pengfei Wang ◽  
Shoutian Sun ◽  
Pengyue Yuan ◽  
...  
1999 ◽  
Vol 14 (1) ◽  
pp. 209-212 ◽  
Author(s):  
Masatoshi Ito ◽  
Won-Son Seo ◽  
Kunihito Koumoto

PbTe thin films with fine grains were successfully fabricated by the gas evaporation method. Thermoelectric properties, i.e., Seebeck coefficient and electrical conductivity, both decreased with decreasing grain size. This was attributed to the decrease in carrier mobility exceeding the increase in carrier concentration with decreasing grain size. It was clarified that the effects of grain boundaries and of oxidation on carrier mobility are considerably large.


2015 ◽  
Vol 1131 ◽  
pp. 39-42
Author(s):  
Narin Tammarugwattana ◽  
Kitipong Mano ◽  
Chaloempol Saributr ◽  
Adirek Rangkasikorn ◽  
Navaphun Kayunkid ◽  
...  

Tin-doped nickel phthalocyanine thin films (Sn-doped NiPc) were deposited by thermal co-evaporation method. Doping concentration of tin in NiPc was controlled via different deposition rates between metal dopent and host organic material. Properties of the thin films doped by tin in the range of 3 to 15% were characterized by atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), UV-Visible spectroscopy and X-ray photoelectron spectroscopy (XPS). Furthermore, electrical properties of Al/Sn-doped-NiPc/ITO devices i.e. charge carrier concentration and carrier mobility were characterized by current-voltage and capacitance-voltage measurements. Microscopic results show clear evidence of the morphological transition from granular structure in undoped-film to rod-liked structure in the films doped more than 5%. Moreover, surface grain size exhibits the tendency to decrease with the increase of doping concentration. Optical properties reveal that the packing of NiPc molecules in all doping conditions is the combination of α-phase (majority) and β-phase (minority). However, evolution of β-phase NiPc is observed with the increase of doping concentration. Photoelectron analyses indicate shift of binding energy in both Ni2p and Sn3d levels corresponding to charge transfer between nickel-core and tin dopant. In addition, the electrical properties show the enhancement of the film’s conductivity due to the increase of charge carrier concentration with the higher Sn-doping level.


2011 ◽  
Vol 99 (7) ◽  
pp. 072114 ◽  
Author(s):  
P. Pichanusakorn ◽  
Y. J. Kuang ◽  
C. J. Patel ◽  
C. W. Tu ◽  
P. R. Bandaru

2007 ◽  
Vol 1020 ◽  
Author(s):  
S. Budak ◽  
S. Guner ◽  
C. Muntele ◽  
C. C. Smith ◽  
B. Zheng ◽  
...  

AbstractSemiconducting â-Zn4Sb3and ZrNiSn-based half-heusler compound thin films were prepared by co-evaporation for the application of thermoelectric (TE) materials. High-purity solid zinc and antimony were evaporated by electron beam to grow the â-Zn4Sb3thin film while high-purity zirconium powder and nickel tin powders were evaporated by electron beam to grow the ZrNiSn-based half-heusler compound thin film. Rutherford backscattering spectrometry (RBS) was used to analyze the composition of the thin films. The grown thin films were subjected to 5 MeV Si ions bombardments for generation of nanostructures in the films. We measured the thermal conductivity, Seebeck coefficient, and electrical conductivity of these two systems before and after 5 MeV Si ions beam bombardments. The two material systems have been identified as promising TE materials for the application of thermal-to-electrical energy conversion, but the efficiency still limits their applications. The electronic energy deposited due to ionization in the track of MeV ion beam can cause localized crystallization. The nanostructures produced by MeV ion beam can cause significant change in both the electrical and the thermal conductivity of thin films, thereby improving the efficiency. We used the 3ù-method measurement system to measure the cross-plane thermal conductivity ,the Van der Pauw measurement system to measure the cross-plane electrical conductivity, and the Seebeck-coefficient measurement system to measure the cross-plane Seebeck coefficient. The thermoelectric figures of merit of the two material systems were then derived by calculations using the measurement results. The MeV ion-beam bombardment was found to decrease the thermal conductivity of thin films and increase the efficiency of thermal-to-electrical energy conversion.


2013 ◽  
Vol 652-654 ◽  
pp. 519-522
Author(s):  
Jun Chen ◽  
Yue Hui Hu ◽  
Hong Hao Hu ◽  
Yi Chuan Chen

Transparent thin films of Sn-doped ZnO (ZnO:Sn) were deposited onto silica glass substrates by the sol–gel method. The effect of different Sn doping on the crystallinity, structural, optical and electrical properties of ZnO:Sn thin films were investigated by XRD, SEM, UV-VIS spectrophotometer and four-point probe method respectively. Among all of ZnO:Sn thin films in this paper, Sn-doped with 2 at.% exhibited the best properties, the surface demonstrate an accumulative crystallization and hexagonal structure, with a high-preferential c-axis orientation, namely an average transmittance of 90% and the resistivity of 19.6 Ω·cm.


2002 ◽  
Vol 240 (3-4) ◽  
pp. 340-346 ◽  
Author(s):  
A.M. Samoylov ◽  
M.K. Sharov ◽  
S.A. Buchnev ◽  
A.M. Khoviv ◽  
E.A. Dolgopolova

2017 ◽  
Vol 5 (35) ◽  
pp. 18808-18815 ◽  
Author(s):  
Yuanbo Yang ◽  
Pengzhan Ying ◽  
Jinzhi Wang ◽  
Xianglian Liu ◽  
Zhengliang Du ◽  
...  

Through coordination of the Seebeck coefficient and carrier concentration in Cu3SnS4, TE performance improves significantly with the ZT value of 0.75 at 790 K.


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.


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