CHAPTER-m CZTS THIN FILMS BY CHEMICAL BATH

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2 CHAPTER-m: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY CHAPTER-III SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY Sr. No TITLE Page No. 3.1 Introduction Experimental details Substrate cleaning Experimental setup for deposition of CZTS 55 thin films by CBD method Deposition of CZTS thin films Characterization of CZTS thin films Characterization techniques CZTS thin film formation and reaction 57 mechanism Thickness measurement Surface morphological studies Atomic force microscopy studies X-ray diffraction (XRD) studies Optical properties 64

3 CHAPTER-III: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY FT-Raman spectroscopy Contact angle measurement Electrical resistivity measurement Thermoemf measurement Conclusions 69 References 70

4 CHAPTER-III: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY CHEMICAL BA 77/ DEPOSITION (CBD) METHOD 3.1 Introduction The methods used for the synthesis of CZTS thin films, include sputtering deposition [1, 2], spray pyrolysis [3], electrodeposition [4, 5], co-evaporation [6], pulsed laser deposition [7], successive ionic layer adsorption and reaction (SILAR) and chemical bath deposition (CBD) [8, 9], The use of low temperature and solution based methods is promising as these methods are cheap and simple. Among these, CBD is the most attracting method. The CBD method has been used to deposit films of metal sulfides and oxides, together with some miscellaneous compounds [10], The CBD is an excellent method to deposit nanocrystalline thin films [11]. It refers to deposition from solution, generally aqueous where the required deposits are chemically generated and deposited in the same bath. The CBD method is based on the slow controlled precipitation of the desired compound from reaction bath solution on to the substrate surface. In CBD, substrate can be coated with desired material directly, which is advantage over the other methods in which final product is in powder form. The method is also useful for large area deposition. Metal oxide films deposited by CBD are reviewed by Pawar et al [12], The present chapter deals with the preparation of CZTS thin films from aqueous alkaline bath and their characterization. Different preparative parameters such as deposition temperature, concentration of precursor solution, ph of the bath etc are optimized to get uniform CZTS thin films. 3.2 Experimental details Substrate cleaning Substrate cleaning plays an important role in the deposition of CZTS thin films. Extreme cleanliness of the substrate is required for the chemical deposition as the contaminated surface provides nucleation sites facilitating growth resulting into nonuniform films with different orientation and impurities. The glass microslides manufactured by Blue Star of dimensions 75 x 25 x l.35 mm3 are used as the substrates. The following procedure is followed for cleaning the substrates: BARR tttumift UMH» 54

5 CHAPTER-III: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY i) The glass slides were washed with detergent and distilled water and boiled in concentrated chromic acid (0.5 M) for 1 hr and kept in it for 24 hr, ii) iii) iv) The substrates were washed with double distilled water, Then, the substrates were ultrasonically cleaned for 1 hr, and Finally, the substrates were dried, degreased in AR grade acetone and were used for deposition Experimental setup for deposition of CZTS films by CBD method The schematic of experimental set-up employed for the growth of the CZTS films using CBD method is shown in Fig It consists of container, usually a glass beaker, bakelite holder and the substrates. The substrates were fitted in the bakelite holder having the two slots and the holder is fixed in a beaker containing the precursor solution. The glass beaker serves two purposes of chemically inertness and visibility inside the bath. Fig. 3.2 shows actual experimental setup for deposition of CZTS thin films. Thermometer Bakelite substrate holder Substrate Reaction hath Hot water bath Temperature Controller Fig. 3.1 Schematic of experimental setup for deposition of CZTS thin films. 55

6 CHAPTER-111: SYNTHESIS AM) CHARACTERIZATION OF CZTS THIN FILMS BY CHEMICAL BA TH DEPOSITION (CBD) METHOD Thermometer Stand Thermometer Bakelite substrate holder Hot water bath 0.01 MCuCl, 0.05 MZnCh, 0.05 M SnCU and 0.5 M NarSzOs Temperature controller Fig. 3.2 Experimental setup for deposition of CZTS thin films Deposition of CZTS thin films The CZTS thin films are deposited on to the glass and stainless steel substrates using chemical bath deposition (CBD) method. Chemicals used are AR grade CuCl, ZnCU, SnCU and Na^SiOi as sources of Cu, Zn, Sn and S' ions, respectively. The chemical bath containing 0.01 M CuCl, 0.05 M ZnCU, 0.05 M SnCU and 0.5 M Na^SiCU solutions in equal volume ratio ( Cu:Zn:Sn:S = 2:1:1:4 ) is prepared by mixing them in a beaker. The ph of the resulting solution is 10±0.1 adjusted using aqueous ammonia. The concentrations of the CZTS precursor solution are varied from 0.01 to 0.5 M at an interval of 0.05 M by changing the amount of CuCl, ZnCU. SnCU and Na2S2CU dissolved in double distilled water (DDW). The CZTS films obtained from CuCl, ZnCU, SnCU and Na:S2CU solutions of concentration <0.5 M are porous and adherent to substrate and the films obtained above 56

CHAPTER-III: SYNTHESIS Am CHARACTERIZATION OF CZTS THIN FILMS BY 0.5 M are powdery. Therefore, the range of solution concentration is considered from 0.01 to 0.5 M in the present study.

7 CHAPTER-III: SYNTHESIS Am CHARACTERIZATION OF CZTS THIN FILMS BY 0.5 M are powdery. Therefore, the range of solution concentration is considered from 0.01 to 0.5 M in the present study. Precleaned glass substrates are immersed in the bath and then the bath is heated up to 358 K for 24 hr. After about 4 hr, the solution becomes blurred and within 24 hr the dark green precipitate is formed in die bath. During the precipitation, the heterogeneous reaction occurs and the deposition of CZTS takes place on the substrates. Further deposited CZTS thin films are air annealed at 673 K. 3.3 Characterization of CZTS thin films Characterization techniques The thickness of film is the most significant parameter and computed by using fully computerized AMBIOS Make XP-1 surface profiler with 1 A vertical resolution. The structural characterization of CZTS thin films was carried out by analyzing X-ray diffraction (XRD) patterns obtained with CrK (a = A) radiation from a Philips X-ray diffractometer model PW-1710 in the span of angle The surface morphological analysis was carried out using scanning electron microscopy (SEM) JEOL JSM model The Raman spectra of the films were recorded in the spectral range of cm-1 using Raman spectrometer (Broker MultiRAM, Germany Make). The optical absorption study was carried out within a wavelength range of nm using a (UV-1800 SHIMADZU) spectrophotometer. The topographic images of CZTS films were recorded with a multimode atomic force microscope (Innova 1B3BE) operating in the tapping mode. The wettability of the film was carried out by Rame-hart USA equippement with CCD camera. A two-probe method was used for electrical resistivity measurement in the temperature range of K. The type of electrical conductivity was determined from thermoemf measurement CZTS film formation and reaction mechanism The CBD method is based on the formation of a solid phase from a solution, which involves two steps of nucleation and particle growth. The film of certain thickness grows by heterogeneous reactions of the Cu+1, Zn+2, Sn44 and S"2 precursor solutions on the substrate surface. When ammonia is added to it, a feint white blue precipitate occurred, which is dissolved by additional ammonia. The possible reaction mechanism for the formation of CZTS thin film is as follows, 57

8 CHAPTER-111: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY 2CuCl + ZnCl2+SnCl4+8H20 >2Cu+1 +Zn+2+Sn+4+8HC1+80H' (3.1) Na2S203 is a reducing agent by virtue of half cell reaction [13], 4S2C>32» S40g2 + 4e (3.2) In acidic medium, dissociation of Na2S203 takes place, S2032 +H+->HS0;+S (3.3) The electrons released (reaction (3.2)) reacts with the sulphur from reaction 2S + 4e»2S 2 (3.4) From reactions (3.1) and reaction (3.4), the final reaction for the formation of CZTS is, 2Cu+1 +Zn+2 +Sn+4 +2S'"2 -> Cu2ZnSnS4 (3.5) Thus, nucleation and growth of CZTS thin films take place via ion-by-ion mechanism. The deposited films are found to be uniform, adherent and appeared dark brown in color Thickness measurement The variation of CZTS film thickness with deposition time is shown in Fig The nonlinear rate of increase in the film thickness is attributed to the growth by nucleation and coalescence process. More nucleation sites contribute to coagulation during the growing procedure. Furthermore, slight decrease in film thickness observed after 24 hr which can be attributed to the formation of outer porous layer and/or the film may have developed stress which tends to cause delamination, resulting in peeling off the film after the film reaches at maximum thickness [14]. In the process of deposition of CZTS films by the CBD method, the bath was kept at 358 K temperature without stirring. It is observed that after 4 hr, precipitation starts and the deposition of CZTS begins by heterogeneous reaction on the substrate surface and the thickness of the film increases with the deposition time. Inset of Fig. 3.3 shows the photograph of CZTS thin films having large area 20 cm2. 58

9 CHAPTER-ID: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY Deposition Time (hr) Fig. 3.3 Variation of CZTS film thickness with deposition time. (Inset shows the photograph of CZTS thin film for the deposition period of 24 hour.) Surface morphological studies The schematic growth model for CZTS thin film is shown in Fig Inset photograph (a) shows actual morphology of as deposited CZTS thin film. The CBD is one of the bottom-up approach methods based on the formation of a solid phase upon transformation of a supersaturated solution to the saturated state. This transformation incorporates various distinct steps as (A) nucleation, (B) aggregation, (C) coalescence and (D) subsequent growth by stacking of the particles. During nucleation, clusters of metal precursor molecules are likely to undergo rapid decomposition. Such nucleation centers act as foundation for the aggregation of the particles (B). Moreover, basic ground work for the nanostructure is formed by coalescence of aggregated particles (C). Subsequently, the film grows to a certain thickness on the substrate surface by stacking of the particles (D) [15]. Scanning electron micrographs of as deposited and annealed CZTS thin films at two different magnifications are presented in Fig.3.5 [(ar-a5, b-b )]. From the micrographs [Fig. 59

10 CHAPTER-111: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY CHEMICAL BA TH DEPOSITION (CBD) METHOD 3.5 (a-a )], it is seen that the film surface of as deposited CZTS film is well covered with randomly distributed interlocked cubes. The approximate size of these cubes is in the range of 2-5 pm. After annealing, these interlocked cubes diffused in to each other to form compact and rough surface as shown in Fig. 3.5 [(b)]. The surface morphology at higher magnification [Fig. 3.5 (b )j depicts that entire surface of the substrate is covered with sharp edge cubes. Tanaka et al. [16] prepared CZTS thin films by sputtering method and reported that film consists of the closely packed grains with sub-micron size. Roundshaped nanoparticles of about 200 nm with homogeneous size distribution are obtained by Todorov et al. [17] using soft chemistry method. Fig. 3.4 (a) The schematic growth model for formation of CZTS thin films: (A) nucleation, (B) aggregation, (C) coalescence and (D) subsequent growth by stacking of the particles. 60

CHAPTER-111: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY CHEMICAL BA TH DEPOSITION (CBD) METHOD X 5,000 10 ^iin X 20,000 2 pm Fig. 3.

11 CHAPTER-111: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY CHEMICAL BA TH DEPOSITION (CBD) METHOD X 5, ^iin X 20,000 2 pm Fig. 3.5 The SEM images at two different magnifications ( X 5000 and X 20,000) of CZTS thin films of as deposited (a and a ) and annealed (b and b ) Atomic force microscopy studies Fig. 3.6 shows AFM image of CZTS film deposited on glass substrate. A topographic AFM image (Fig.3.6) demonstrate continuous growth of CZTS thin film with randomly distributed different sized particles in the order of 2-4 pm width and 1 pm height over the surface roughness 225 nm [18]. Similar type of result was obtained for CZTS thin film deposited by dip-coating method [19], 61

12 CHAPTER-III: SYNTHESIS AND CHARACTERIZATION OE CZTS THIN FILMS BY CHEMICAL BA TH DEPOSITION (CBD) METHOD r«- 73* f > vj, ' V.r * 1.0 ur/ Ri # / Fig 3.6 The AFM 3D image of CZTS thin film on glass substrate X-ray Diffraction (XRD) studies Fig. 3.7 shows XRD patterns of (a) as deposited and (b) air annealed at 673 K CZTS thin films on glass substrate. Inset of Fig. 3.7 (a, b) shows the photographs of asdeposited and annealed CZTS thin films. No distinct diffraction peak is observed in XRD pattern of as deposited film, which probably means that the film consisted of hydrous CZTS colloidal particles with low crystallinity. Intensity of characteristics peaks of CZTS is increased after heat treatment and six broad XRD peaks are assignable to (002), (112), (110), (200), (220) and (111) planes. Observed d values are in good agreement with standard d values (JCPDS card no ), which confirms formation of kesterite type of CZTS thin films. Also, from the XRD patterns, it is revealed that as deposited CZTS thin film is amorphous while annealed CZTS thin films is nanocrystalline. It is noted that ZnS (JCPDS card no ), having a blend structure exhibits three XRD planes (112), (200) and (220), which are difficult to distinguish from those of kesterite type CZTS thin film. On other hand, crystal phase of SnS: (JCPDS card no ) is also observed at diffraction peak (111). Similar type of result has been obtained by Torimoto et al. [20] for thermal reaction deposited CZTS films. It should be noted that the relative peak 62

13 CHAPTER-111: SYNTHESIS AND CHARACTERIZATION OE CZTS THIN FILMS BY CHEMICAL BA TH DEPOSITION (CBD) METHOD intensity of the diffraction arising from (110) of CZTS plane is much stronger than other. High temperature treatment could increase the crystallinity and grain size of CZTS films, which conduces to fabricate high efficiency solar cell because the efficiency of polycrystalline solar cell increases with an increase in grain size of the absorber [21], Mali et al. also observed similar type of result for SILAR deposited CZTS thin film [22], The crystallite size 63 nm of CZTS thin film from XRD pattern is calculated using equation 2.9. ZnS ( ) SnS, ( ) CZTS ( ) I n t e n s i t y (A.IX.) CO 2 to t- h»- N N N u Si u f? 2 2 H CO h N0 O o & JL /**s O (S a CO h- N 0 CO M Fig. 3.7 The XRD patterns of (a) as deposited and (b) annealed CZTS thin fdms on glass substrate. Reference XRD patterns of bulk CZTS, ZnS and SnS2 materials are also shown for comparison. (Inset shows photographs of (a) as deposited and (b) annealed CZTS thin film on glass substrate). 63

14 CHAPTER-HI: SYNTHESIS Am CHARACTERIZATION OF CZTS THIN FILMS BY Optical properties The optical absorption of as deposited and annealed CZTS thin films in the wavelength range nm is studied. Inset of Fig. 3.8 (a and b) shows variation of absorbance (at) of as deposited and annealed CZTS film with wavelength (X). These spectra revealed that as deposited and annealed CZTS thin films have high absorbance of light in the visible region, indicating applicability as an absorbing material. Optical absorption increases of for annealing which may be due to increase in crystallite size and/or decrease in defects [23]. The optical band gap energy is estimated by using the equation (2.10). Fig. 3.8 (a and b) shows the variation of (dm)2 versus hu plots. The plots are straight lines in the domain of higher energies, indicating direct optical transitions. Extrapolation of these curves to zero absorption coefficients (of=0) gives the optical energy gap as 1.7 ev for as deposited and 1.5 ev for annealed CZTS thin films. The decrease in band gap after annealing is a consequence of phase change from amorphous to nanocrystalline nature. The decrement in the band gap is in agreement with the earlier reports for CZTS thin films [24], The decrement in the band gap energy from 2.7 to 1.5 ev after annealing is reported by Pawar et al. [24] for electrodeposited CZTS thin films. The band gap of CZTS film is quite close to the optimum band gap required for a solar cell, which indicates that CZTS is a promising material for thin film solar cell application. 64

15 CHAPTER-IU: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY Photon energy, hv (ev) Fig.3.8 The plots of (oho)2 vs. ho of (a) as deposited and (b) annealed CZTS thin films. (Inset shows variation of absorbance (at) with wavelength (X) for CZTS thin films on glass substrate) FT-Raman spectroscopy The FT-Raman spectra recorded over cm-1 of CZTS thin films are shown in Fig. 3.9 (a, b) Raman spectra confirmed the existance of the kesterite CZTS with well defined peaks at 258, 283, and 287 cm-1 which are in good agreement with previously reported Raman spectrum of CZTS thin film [25-26]. These peals confirm the formation of kesterite structure of CZTS stretching mode. Also FT-Raman spectra confirmed the presence of ZnS with blend structure and SnS phases. FT-Raman analyses indicate the formation of crystal phases as ZnS and SnS, SnS2 at 274, 314, 304 cm-1, respectively [27-28]. The XRD and FT-Raman analyses indicate that the formed films are kesterite CZTS thin films along with a mixture of ZnS and SnS. 65

16 i5 < CHAPTER-III: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY K> t Lh ii B SB Cft. oo S3- cy» 5? 2 w s S I I * U \ Fig. 3.9 FT-Raman spectra of (a) as deposited and (b) annealed CZTS thin films Contact angle measurement In order to study the interaction between electrode and electrolyte, the wettability test is carried out. The wetting behavior is characterized by the value of the contact angle, a microscopic parameter. If the wettability is high, contact angle (0), is the small and the surface is hydrophilic [29]. On the contrary, if the wettability is low, 0 is large and the surface is hydrophobic. The contact angle is an important parameter in surface science and its measurement provides a simple and reliable technique for die interpretation of surface energies. The method involves the measurement of contact angle between water and the thin film electrode. The contact angle is expected to depend upon local homogeneity, chemical composition and the surface morphology of the semiconducting electrodes [30]. Fig (a, b) shows the water contact images of as-deposited and annealed CZTS films, respectively. The contact angles for as deposited and annealed CZTS thin films are found to be 46 and 65, respectively. Increase in water contact angle after annealing is attributed 66

17 CHAPTER-IH: S YNTHESIS AND CHARA CTERIZA TION OF CZTS THIN FILMS B Y CHEMICAL BA TH DEPOSITION (CBD) METHOD to (i) non-spherical nature of the grains and (ii) topographical change in structure. Similar type of increase in contact angle after annealing has been reported by Shinde et al for ZnO thin films [31], WI (bf Contact angle = 46? * I Contact angle = 65 Fig Contact angle measurement of (a) as deposited and (b) annealed CZTS thin films Electrical resistivity measurement The d. c. two probe method was employed to study the variation of electrical resistivity with temperature for CZTS thin films. Fig (a, b) shows the variation of log (p) with reciprocal of temperature (1000/T) for CZTS thin film. The electrical resistivity of as deposited and annealed CZTS films was decreased with increase in temperature, indicating the normal semiconducting behavior. The activation energy is calculated using the relation For both as deposited and annealed CZTS films, there is a single distinct activation energy regime indicating single conduction mechanism. It is found that as-deposited CZTS thin film exhibits room temperature electrical resistivity equal to 104 Q-cm. which decreases to 103 fl-cm after annealing at 673 K. The activation energies are \found to be 0.62 and 0.67 ev for as deposited and annealed CZTS thin films, respectively. The increase in the activation energy may be attributed to the modifications of defect states [32]. Kumar et al. [33] reported similar semiconducting behavior of CZTS thin films deposited by spray pyrolysis method. 67

18 CHAPWR-HI: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY Log (p) - fc, 14 f T mottqjk) Fig Variation of dark electrical resistivity (log p) with reciprocal temperature (1000/T) of (a) as deposited and (b) annealed CZTS thin films Thermoemf measurement In the thermoemf measurement, the temperature difference causes the transport of carriers from the hot end to the cold end and thus creates an electric field, which gives the thermal voltage. The dependence of thermoelectric emf (induced emf) on temperature is depicted in Fig The plot shows that an increase in the temperature difference results in increased induced emf. This is attributed to the increase in carrier concentration and/or the mobility of charge carriers with a rise in temperature. Induced emfs measured at 200 C temperature difference for as deposited and annealed CZTS thin film are found to be 11.5 and 4.7 mv/ C, respectively. Induced emf of as-deposited film is higher than annealed film which may be due to lesser number of defect levels [29]. The polarity of the induced emf for as deposited and annealed CZTS film indicates a p-type electrical conductivity. It is 68

19 CHAPTER-1 II: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY CHEMICAL BA TH DEPOSITION (CBD) METHOD found that the polarity of thermoemf for both as deposited and annealed CZTS thin film is in favor of p-type conductivity, as reported by Tanaka and Kumar et al. [16, 33], 25 Thermoemf (mv) ux u Fig, 3,12 Thermoemf measurement of (a) as deposited and (b) annealed CZTS thin films. 3.4 Conclusions Deposition of uniform and adherent CZTS thin film is carried out by simple and inexpensive chemical bath deposition method on to the glass substrates. These films were annealed at 673 K for 4 hr. From XRD pattern, it is revealed that the as deposited CZTS thin films are amorphous while annealed CZTS thin films are nanoycrystalline. The optical energy band gap is decreased after annealing. The decrease in band gap is a consequence of phase change from amorphous to nanocrystalline nature. FT-Raman confirms that the CZTS films are keserite along with a mixture of ZnS and SnS2. The contact angle 69

20 V- CHAPTER-IU: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY measurement concluded that CZTS thin films are hydrophilic in nature. The electrical resistivity decreased from 104 to 103 Q-cm after annealing, due to removal of hydroxide and other impurities from as deposited CZTS films. Thermoemf measurement confirmed that CZTS films have p-type electrical conductivity. 70

21 CHAPTER-III: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY References [1] J. S. Seol, S. Y. Lee, J. C. Lee, H. D. Nam, K. H. Kim, Sol. Energy Mater. Sol. Cells 75 (2003) 155. [2] A. I. Inamdar, Seulgi Lee, Ki-Young Jeon, Chong Ha Lee, S.M. Pawar, R.S. Kalubarme, Chan Jin Park, Hyunsik Im, Woong Jung, Hyungsang Kim. Sol. Energy 91 (2013) 196. [3] N. Nakayama and K. Ito, Appl. Surf. Sci. 92 (1996) 171. [4] H. Araki, Y. Kubo, A. Mikaduki, K. Jimbo, W. Maw, H. Katagiri, M. Yamazaki, K. Oishi, A. Takeuchi, Sol. Energy Mater. Sol. Cells 93 (2009) 996. [5] R. Schurr, A. Hoelzing, S. Jost, R. Hock, T. Vob, J. Schulze, A. Kirbs, A. Ennaoui, M. Lux-Steiner, A. Weber, I. Koetschau, H. Schock, Thin Solid Films 517 (2009) [6] K. Oishi, G. Saito, K. Ebina, M. Nagahashi, K. Jimbo, W. Maw, H. Katagiri, M. Yamazaki, H. Araki, A. Takeuchi, Thin Solid Films 517 (2008) [7] EL Tanaka, N. Moritake, H. Uchiki, Sol. Energy Mater. Sol. Cells 91 (2007) [8] N. M. Shinde, D. P. Dubai, D. S. Dhawale, C. D. Lokhande, J. H. Kim, J. H. Moon, Mater. Res. Bull. 47 (2012) 302. [9] N. M. Shinde, C. D. Lokhande, J. H. Kim, J. H. Moon, J. Photochem. Photobiol: A 235 (2012) 14. [10] R, S. Mane and C. D. Lokhande, Mater. Chem. Phys., 65 (2000) 1. [11] G. Hodes, Phys. Chem. Chem. Phys. 9 (2007) [12] S. M. Pawar, B. S. Pawar, J. H. Kim, Oh-Shim Joo, C. D. Lokhande, Curr. Appl. Phy. 11(2011)117. [13] C. D. Lokhande, Mata-. Chem. Phys. 26 (1990) 405. [14 J. Thorton, J. Vac. Sci. A 24 (1986) [15] V. R. Shinde, C. D. Lokhande, R. S. Mane, S.H. Han, Appl. Surf. Sci. 245 (2005) 407. [16] T. Tanaka, T. Nagatomo, D. Kawasaki, M. Nishio, Q. Guo, A. Wakahara, A. 71

22 V* i ft", JfTt CHAPTER-HI: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY Yoshida, H. Ogawa, J. Phys. Chem. Solid 66 (2005) [17] T. Todorov, M. Kita, J. Carda, P. Escribano, Thin Solid Films 517 (2009) [18] G. Rajesh, N. Muthukumarasamy, E. P. Subramaniam, S. Agilan, Dhayalan Velauthapillai, J. Sol-Gel. Sci. Technol 66 (2013) 288. [19] Y. Wen, L. Li, Y.Dong, M. Yao, Q. Liang, 2na International Conference on Electronic & Mechanical Engineering and Information Technology (EMEIT-2012), Published by Atlantis Press, Paris, France. [20] T. Kameyama, T. Osaki, K. Okazaki, T. Shibayama, A. Kudo, S. Kuwabatade, T. Torimoto, J. Mater. Chem. 20 (2010) [21] S. M. Pawar, A. V. Moholkar, I. K. Kim, S. W. Shin, J. H. Moon, J. I. Rhee, J. H. Kim, Cuir. AppL Phy. 10 (2010) 565. [22] S. S. Mali, B. M. Patil, C. A. Betty, P. N. Bhosale, Y. W. Ohd, S. R. Jadkare, R. S. Devan, Y. R. Ma, P. S. Patil, Electrochim. Acta 66 (2012) 216. [23] R. B. Kale and C. D. Lokhande, Appl. Surf. Sci. 252 (2005) 929. [24] S. M. Pawar, B.S. Pawar, A.V. Moholkar, D. S. Choi, J. H. Yun, J. H. Moon, S. S. Kolekar,J. H. Kim, Electrochim. Acta 55 (2010) [25] H. Nukala, J. Johnson, A. Bhatia, E. Lund, W. Hlaing, M. Nowell, L. Rieth, M. Scarpulla, Mater. Res. Soc. Symp. Proc EE [26] K. Wang, O. Gunawan, T. Todorov, B. Shin, S. Chey, N. Bojarczuk, D. Mitzi, S. Guhaa, Appl. Phys. Lett. 97 (2010) [27] C. Zou, L. Zhang, D. Lin, Y. Yang, Q. Li, X. Xu, X. Chen, S. Huang, Cryst. Eng. Comml3 (2011) [28] A. Famades, P. Salome, A. Chuna, J. Alloys Compd. 509 (2009) [29] C. D. Lokhande, A. Barkschat, H. Tributsch, Sol. Energy Mater. Sol. Cells 79 (2003)293. [30] R. Sun, A. Nakajima, A. Fujushima, T. Watanabe, K. Hashimoto, J. Phys. Chem. B 72

23 CHAPTER-III: SYNTHESIS AND CHARACTERIZATION OF CZTS THIN FILMS BY 105 (2001) [31] V. R. Shinde, C. D. Lokhande, R. S. Mane, S. H. Han, Appl. Surf. Sci. 245 (2005) 407. [32] B. R. Sankapal and C. D. Lokhande, Mater. Chem. Phy. 74 (2002) 126. [33] Y. B. Kishore Kumar, G. Suresh Babu, P. Uday Bhaskar, V. Sundara Raja, Sol. Energy Mater. Sol. Cells 93 (2009)

Applications of Successive Ionic Layer Adsorption and Reaction (SILAR) Technique for CZTS Thin Film Solar Cells

Applications of Successive Ionic Layer Adsorption and Reaction (SILAR) Technique for CZTS Thin Film Solar Cells NANO VISION An International Open Free Access, Peer Reviewed Research Journal www.nano-journal.org ISSN 2231-2579 (Print) ISSN 2319-7633 (Online) Abbr: Nano Vision. 2013, Vol.3(3): Pg.235-239 Applications