Effect of pH on the characteristics of nanocrystalline ZnS thin films prepared by CBD method in acidic medium

被引:60
作者
Kang, So Ra [1 ]
Shin, Seung Wook [1 ]
Choi, Doo Sun [1 ]
Moholkar, A. V. [1 ,2 ]
Moon, Jong-Ha [1 ]
Kim, Jin Hyeok [1 ]
机构
[1] Chonnam Natl Univ, Dept Mat Sci & Engn, Kwangju 500757, South Korea
[2] Gopal Krishna Gokhale Coll, Dept Phys & Elect, Thin Film Lab, Kolhapur 416012, Maharashtra, India
关键词
Chemical bath deposition; ZnS thin films; X-ray diffraction; FE-SEM; XPS; CHEMICAL BATH DEPOSITION; BUFFER LAYERS; SOLAR-CELLS; CDS; ROUTE;
D O I
10.1016/j.cap.2010.02.052
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The structural, morphological, and optical properties of zinc sulfide (ZnS) thin films deposited using chemical bath deposition method are reported. These films were deposited on soda lime glass substrates using Na(2)EDTA as a complexing agent, in acidic medium at 80 degrees C. The effect of the pH ranging from 5 to 6.5 on quality of ZnS thin films is investigated. Irrespective of the pH values used for the deposition all films are polycrystalline with a wurtzite (hexagonal) structure. Field emission scanning electron microscopy (FE-SEM) characterization shows that the surface of the sample deposited with pH 5 and 5.5 is compact and uniform. However, agglomerated clusters (similar to 100 nm) are observed in ZnS thin films grown with pH above 6. X-ray photoelectron spectroscopy results shows the presence of only Zn-S bonding for the ZnS thin film grown at pH = 5 while those films deposited with pH > 5.5, Zn-OH as well as Zn-S bonding have been observed. The composition is almost stoichiometric for a wide range of pH values of the solution (5-6.5). The transmission spectrum of ZnS thin films having thickness from 30 to 220 nm indicates a good transmission characteristic with an average transmittance of 70-85%. The absorption coefficient depends on the pH values of the solution used and are responsible to the changes observed in absorption edges. The band gap energy values of ZnS thin films decreased from 3.91 to 3.78 eV with increasing pH values of the solution. (C) 2010 Elsevier B. V. All rights reserved.
引用
收藏
页码:S473 / S477
页数:5
相关论文
共 24 条
[1]   Study of CuInS2/ZnS/ZnO solar cells, with chemically deposited ZnS buffer layers from acidic solutions [J].
Asenjo, B. ;
Chaparro, A. M. ;
Gutierrez, M. T. ;
Herrero, J. ;
Klaer, J. .
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 2008, 92 (03) :302-306
[2]  
BERGER LI, 1997, SEMICOND MAT, P1997
[3]   Cu(In,Ga)Se2 thin-film solar cells with ZnS(O,OH), Zn-Cd-S(O,OH), and CdS buffer layers [J].
Bhattacharya, RN ;
Ramanathan, K ;
Gedvilas, L ;
Keyes, B .
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 2005, 66 (11) :1862-1864
[4]   Synthesis and characterization of some ZnS-based thin film phosphors for electroluminescent device applications [J].
Dimitrova, V ;
Tate, J .
THIN SOLID FILMS, 2000, 365 (01) :134-138
[5]   Highly efficient Cu(Ga,In)(S,Se)2 thin film solar cells with zinc-compound buffer layers [J].
Ennaoui, A ;
Eisele, W ;
Lux-Steiner, M ;
Niesen, TP ;
Karg, E .
THIN SOLID FILMS, 2003, 431 :335-339
[6]   Investigations on the physical properties of the polycrystalline ZnS thin films deposited by the chemical bath deposition method [J].
Gode, F. ;
Gumus, C. ;
Zor, M. .
JOURNAL OF CRYSTAL GROWTH, 2007, 299 (01) :136-141
[7]   Ammonia-free chemical bath deposition of nanocrystalline ZnS thin film buffer layer for solar cells [J].
Goudarzi, Alireza ;
Aval, Ghaffar Motedayen ;
Sahraei, Reza ;
Ahmadpoor, Hiva .
THIN SOLID FILMS, 2008, 516 (15) :4953-4957
[8]   Thermodynamic and experimental study of chemical bath deposition of Zn(S,O,OH) buffer layers in basic aqueous ammonia solutions.: Cell results with electrodeposited CuIn(S,Se)2 absorbers [J].
Hubert, C. ;
Naghavi, N. ;
Canava, B. ;
Etcheberry, A. ;
Lincot, D. .
THIN SOLID FILMS, 2007, 515 (15) :6032-6035
[9]   Deposition of CdS and ZnS from aqueous solutions by a new photochemical technique [J].
Ichimura, M ;
Goto, F ;
Ono, Y ;
Arai, E .
JOURNAL OF CRYSTAL GROWTH, 1999, 198 :308-312
[10]   Chemical bath deposition of zinc sulfide based buffer layers using low toxicity materials [J].
Johnston, DA ;
Carletto, MH ;
Reddy, KTR ;
Forbes, I ;
Miles, RW .
THIN SOLID FILMS, 2002, 403 :102-106