Thermal Annealing Influence over Optical Properties of Thermally Evaporated SnS/CdS Bilayer Thin Films

Subject Areas : Journal of Optoelectronical Nanostructures

Zahra Dehghani Tafti ¹ (Department of Physics, Faculty of Basic Sciences, Payame Noor University, Tehran, Iran)
Mahmood Borhani Zarandi ² (Atomic and Molecular Group, Faculty of Physics, Yazd University, Yazd, Iran)
Hojjat Amrollahi Bioki ³ (Department of Physics, Tarbiat Modares University, Tehran, Iran)

Received: 2018-10-13 Accepted : 2019-04-21 Published : 2019-01-01

Keywords: CdS, Thin Film, Optical Properties, SnS, Thermal Annealing, Vacuum Evaporation,

Abstract :

Thin films of tin sulfide/cadmium sulfide (SnS/CdS) were prepared by
thermal evaporation method at room temperature on a glass substrate and then annealed
at different temperature with the aim of optimizing the optical properties of the material
for use in photovoltaic solar cell devices. The effect of annealing on optical properties
of SnS/CdS film was studied in the temperature range of 100 to 400 °C with steps of
100 °C. The films were characterized by optical absorption spectra. The optical
constants such as band gap, refractive index (n) and extinction coefficient (k) were
calculated on different annealing temperature and in the wavelength range of 250 nm to
750 nm. Analysis of the optical absorption coefficient demonstrated the presence of
direct optical transition and the corresponding band gap values showed enhancement as
deposition annealing temperature increased. The energy band gap in the range 2.20 eV –
3.18 eV has been obtained for a film as-deposited which increases clearly with
increasing annealing temperature. The refractive index and extinction coefficient both
decrease notably with increasing annealing temperature.

References:

[1] E. Guneri, F. Gode, C. Ulutas, F. Kirmizigul, G. Altindemir, C. Gumus. Properties of p-type SnS thin films prepared by chemical bath deposition. Chalcogenide Letters. 7 (12) (2010) 685-694.
[2] A. Mukherjee, P. Mitra. Structural and optical characteristics of SnS thin film prepared by SILAR. Materials Science-Poland. 33 (4) (2015) 847-851.
[3] S. Hegde, A. Kunjomana, M. Prashantha, C. Kumar, K. Ramesh. Photovoltaic structures using thermally evaporated SnS and CdS thin films. Thin Solid Films. 545 (2013) 543-547.
[4] A. Abdelrahman, W. Yunus, A. Arof. Optical properties of tin sulphide (SnS) thin film estimated from transmission spectra. Journal of non-crystalline solids. 358 (12) (2012) 1447-1451.
[5] S. Ahmed, L. Latif, A. Salim. The effect of substrate temperature on the optical and structural properties of tin sulfide thin films. Journal of Basrah Researches ((Sciences)) Volume. 37 (3A/15) (2011)
[6] E. Guneri, C. Ulutas, F. Kirmizigul, G. Altindemir, F. Gode, C. Gumus. Effect of deposition time on structural, electrical, and optical properties of SnS thin films deposited by chemical bath deposition. Applied Surface Science. 257 (4) (2010) 1189-1195.
[7] A. Mirkamali. Numerical Simulation of CdS/CIGS Tandem Multi-Junction Solar Cells with AMPS-1D. Journal of Optoelectronical Nanostructures. 1 (4) (2017) 31-40.
[8] W. Daranfed, M. Aida, N. Attaf, J. Bougdira, H. Rinnert. Cu 2 ZnSnS 4 thin films deposition by ultrasonic spray pyrolysis. Journal of Alloys and Compounds. 542 (2012) 22-27.
[9] M. Mahdi, S. Kasem, J. Hassen, A. Swadi. Structural and optical properties of chemical deposition CdS thin films. International Journal Nanoelectronics and Materials. 2 (2009) 163-172.
[10] M. Becerril, H. Silva-López, O. Zelaya-Angel, J. R. Vargas-Garcia. Au doping of CdS polycrystalline films prepared by co-sputtering of CdS-Cd-Au targets. Superficies y vacío. 25 (4) (2012) 214-217.
[11] R. Mane, C. Lokhande. Chemical deposition method for metal chalcogenide thin films. Materials Chemistry and Physics. 65 (1) (2000) 1-31.
[12] Y. V. Subbaiah, P. Prathap, K. R. Reddy. Structural, electrical and optical properties of ZnS films deposited by close-spaced evaporation. Applied Surface Science. 253 (5) (2006) 2409-2415.
[13] H. Alexander, H. Teichler. Dislocations. Materials science and technology. (1991)
[14] H. Izadneshan, G. Solookinejad. Effect of Annealing on Physical Properties of Cu2ZnSnS4 (CZTS) Thin Films for Solar Cell Applications. Journal of Optoelectronical Nanostructures. 3 (2) (2018) 19-28.
[15] V. G. Klyuev, D. V. Volykhin, O. V. Ovchinnikov, S. I. Pokutnyi. Relationship between structural and optical properties of colloidal CdxZn1− xS quantum dots in gelatin. Journal of Nanophotonics. 10 (3) (2016) 033507-033507.
[16] X.-Q. Zhang, J.-B. Chen, W.-D. Zhu, C.-W. Wang. Enhanced field emission from hydrogenated SnO2 nanoparticles embedded in TiO2 film on fluorinated tin oxide substrate. Journal of Vacuum Science & Technology B. 32 (2) (2014) 021808.
[17] M. Borhani Zarandi, H. Amrollahi Bioki. Effects of Cobalt Doping on Optical Properties of ZnO Thin Films Deposited by Sol–Gel Spin Coating Technique. Journal of Optoelectronical Nanostructures. 2 (3) (2017) 33-44.
[18] J. Tauc. Optical properties and electronic structure of amorphous Ge and Si. Materials Research Bulletin. 3 (1) (1968) 37-46.
[19] A. Abdel Haleem, M. Ichimura. Experimental determination of band offsets at the SnS/CdS and SnS/InS x O y heterojunctions. Journal of Applied Physics. 107 (3) (2010) 034507.
[20] A. Mirkamali, K. Muminov. The effect of change the thickness on CdS/CdTe tandem multi-junction solar cells efficiency. Journal of Optoelectronical Nanostructures. 2 (2) (2017) 13-24.
[21] K. Saw, N. Aznan, F. Yam, S. Ng, S. Pung. New insights on the burstein-moss shift and band gap narrowing in indium-doped zinc oxide thin films. PloS one. 10 (10) (2015) e0141180.
[22] C. Benouis, M. Benhaliliba, A. S. Juarez, M. Aida, F. Chami, F. Yakuphanoglu. The effect of indium doping on structural, electrical conductivity, photoconductivity and density of states properties of ZnO films. Journal of Alloys and Compounds. 490 (1) (2010) 62-67.
[23] S. Zaynobidinov, R. Ikramov, R. Jalalov. Urbach energy and the tails of the density of states in amorphous semiconductors. Journal of Applied Spectroscopy. 78 (2) (2011) 223-227.
[24] N. Prtljaga, D. Navarro-Urrios, A. Tengattini, A. Anopchenko, J. M. Ramírez, J. M. Rebled, S. Estradé, J.-P. Colonna, J.-M. Fedeli, B. Garrido. Limit to the erbium ions emission in silicon-rich oxide films by erbium ion clustering. Optical Materials Express. 2 (9) (2012) 1278-1285.
[25] R. Swanepoel. Determination of the thickness and optical constants of amorphous silicon. Journal of Physics E: Scientific Instruments. 16 (12) (1983) 1214.