Sains Malaysiana 38(1): 85-89(2009)

 

 

Synthesis and Characterization of MoS2 Films for Photoelectrochemical Cells

(Sintesis dan Pencirian Filem MoS2  untuk Sel Fotoelektrokimia)

 

T. Joseph Sahaya Anand

Department of Materials Science, AIMST University

Jalan Semeling, 08100 Kedah, Malaysia

 

Received:  28 February 2008 / Accepted:  29 Mei 2008

 

 

ABSTRACT

Molybdenum disulfide (MoS2) is a VI – VI compound semiconductor has hexagonal structure useful for high temperature lubricant. Polycrystalline films are electrodeposited cathodically on tin oxide (SnO2) coated conducting glass substrates. The deposited films are characterized by various techniques includes the X-ray diffraction analysis, where the structure of the films is identified as hexagonal and the lattice parameters are a = b = 3.153 Å and c = 12.279 Å which are in good agreement with standard report values. From optical analysis, the bandgap value is calculated as 1.68 eV with indirect bandgap nature. From scanning electron micrographs, the surface appears to be comparatively granular with grains in irregularly shaped. The thickness of the MoS2 films was calculated in the region 0.80 – 0.82 mm by using weight gain method.  From Mott-Schottky plots the films are found to be n-type and the semiconductor parameters of the film are derived. From the photoelectrochemical cell studies the fill factor, open circuit voltage, short circuit current and efficiency are calculated.

 

Keywords: Electrodeposition; MoS2 thin film; Mott-Schottky plot; Photoelectrochemical cell; Semiconductor

 

 

ABSTRAK

 

Molibdenum disulfida (MoS2) merupakan semikonduktor sebatian VI-VI yang mempunyai struktur heksagonal dan S2 berguna sebagai pelincir suhu tinggi.  Filem polihablur dielektroendapkan secara katod di atas substrat kaca yang disalut timah oksida (SnO2) yang mengkonduski. Filem yang diendapkan telah dicirikan dengan berbagai teknik termasuklah analisis pembelanan sinar-X dan struktur filem dikenal pasti sebagai heksogonad dengan parameter kekisi a = b = 3.153 Å dan C= 12.279 Å.  Ini adalah bertepatan dengan nilai piawai yang telah dilaporkan.  Daripada analisis optik, nilai jurang tenaga tak langsung yang dikira ialah 1.68 eV. Mikrograf elektron imbasan menunjukkan permukaan yang berbutiran dengan bentuk yang tidak sekata. Ketebalan filem MoS2 yang diukur menggunakan kaedah tambah berat  adalah di antara 0.80 – 0.82 mm. Plot Mott-Schottky menunjukkan filem tersebut adalah semikonduktor jenis – n.  Daripada kajian faktor pengisian sel fotoelektrokimia, voltan litar terbuka, arus pintas dan kecekapan telah dikira.

 

Kata kunci:  Elektroendapan; filem nipis  MoS2, Plot Mott-Schottky; sel fotoelektrokimia; semikonduktor

 

 

REFERENCES/RUJUKAN

 

 

Afanasiev,  P2008. Synthetic approaches to the molybdenum sulfide materials, Comptes Rendus Chimie, 11: 159-182.

Anand, T.J.S., Ng, H.P., Ngan, A.H.W. & Meng, X.K.  2003. Temperature-coefficient-of-resistance characteristics of sputter-deposited NixAl1-x thin films for 0.5 < x < 1, Thin solid films 441: 298-306.

Charron, L., Dumchenko, D., Fortin, E., Gherman, C. & Kulyuk, L. 2005. Radiative recombination of excitons in the transition-metal dichalcogenides MoS2:Cl2 and WS2:Br2.  Journal of Luminescence 112 : 45-49.

Daming, Z., Jiajun, L., Baoliang, Z. & Wenzhi, L. 1997. A study of the friction and wear performance of MoSx thin films produced by ion beam enhanced deposition and magnetron sputtering, Wear 210: 45-49.

Ferrer, J.,  Chao, P.D., Pascual, A. & Sánchez, C. 2007. An investigation on palladium sulphide (PdS) thin films as a photovoltaic material, Thin Solid Films 515: 5783 – 5786.

Grosseau - Poussard, J.L., Garem, H. & Moine, P. 1996. High resolution transmission electron microscopy study of quasiamorphous MoSx coatings.  Surface and Coatings Technology 78: 19-25.

Grosseau – Poussard, J.L., Moine, P. & Brendle, M. 1997. Shear strength measurements of parallel MoSx thin films. Thin Solid Films 307: 163-168.

Hadouda, H., Pouzet, J., Bernede, J.C. & Barreau, A. MoS2 thin film synthesis by soft sulfurization of a molybdenum layer.  Materials Chemistry and Physics 42: 291-297.

Joseph Sahaya Anand,  T., 2007. Soft selenization of transition metal chalcogenide MoSe2 films for PEC cells. Paper presented at the Malaysian Science and Technology Congress – MSTC 2007, September 4–6, (2007): 142-149.

Joseph Sahaya Anand, T., Sanjeeviraja, C. & Jayachandran, M., 2001.  Preparation of layered semiconductor (MoSe2) by electrosynthesis, Vacuum 60: 431-435.

Liu, Y.R.,  Liu, J.J. & Du, Z., 1999. The cutting performance and wear mechanism of ceramic cutting tools with MoS2 coating deposited by magnetron sputtering, Wear 231: 285-292.

McMurdie, H.F.,  Morris, M.C.,  Evans, E.H.,  Paretzkin, B.  &  Ng, W.W. 1986. Methods of producing standard X-ray diffraction powder patterns. Powder Diffraction 1: 40 - 43.

Mattern,N., Hermann, H., Weise, G., Teresiak A. & Bauer, H.D., 1997. Structure and properties of MoS2 films, Materials Science Forum 235-238: 613-618.

Palit, D., Srivastava, S.K.,  Chakravorti, M.C. & Samantaray, B.K. 1997. “Studies on layer disorder, rnicrostructural parameters and other properties of tantalum substituted tungsten-molybdenum selenide, W0.65Mo0.35-xTaxSe2, (0 ≤ x ≤ 0.35)”, Materials Chemistry and Physics 49: 22-28.

Patil, R.S., 1999. Electrosynthesis of the molybdenum disulphide thin films and characterization.  Thin Solid Films 340: 11-12.

Pouzet, J., Hadouda, H., Bernede, J.C. & Leny, R. 1996. MoS2 thin films obtained by a new technique: Solid state reaction between the constituents in thin Film form.  Journal of Physics and Chemistry of Solids, 57: 1363-1369.

Ponomarev, E.A., Spallart, M.N., Hodes G. & Clement, C.L. 1996. Electrochemical deposition of MoS2 thin films by reduction of tetrathiomolybdate. Thin Solid Films 280: 86-89.

Roy, P. & Srivastava, S.K. 2006. Chemical bath deposition of MoS2 thin film using ammonium tetrathiomolybdate as a single source for molybdenum and sulphur, Thin Solid Films 496: 293-298.

Vollath, D. & Szabo, D.V. 1998.  Synthesis of nanocrystalline MoS2 and WS2 in a microwave plasma. Materials Letters 35: 236-244.

 

 

previous