ABSTRACT Thin films of CdS of different thickness have been prepared on glass substrates in various temperatures by Chemical bath deposition. The thickness of the films has been determined by quartz crystal monitor method. The Hall Effect and the electrical resistivity have been and continue to be the key parameters used in the investigations of the basic electrical conduction processes in semiconductor materials

D Kathirvel

N Suriyanarayanan

S Prabahar

S Srikanth

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International Journal of Physics (IJP), Volume 1, Issue 1, January- March 2012 
15 
 
 
 
 
 
 
HALL EFFECT OF CHEMICAL BATH DEPOSITED  
 CdS THIN FILMS  
D Kathirvel a*, N Suriyanarayanan b, S Prabahar c, S Srikanth c 
a* Department of Physics, Kalaignar Karunanidhi Institute of Technology, Coimbatore, India 
b Department of Physics, Government College of Technology, Coimbatore, India. 
c Department of Physics, Tamilnadu College of Engineering, Coimbatore, India. 
ABSTRACT 
 Thin films of CdS of different thickness have been prepared on glass substrates in 
various temperatures by Chemical bath deposition. The thickness of the films has been 
determined by quartz crystal monitor method. The Hall Effect and the electrical resistivity 
have been and continue to be the key parameters used in the investigations of the basic 
electrical conduction   processes in semiconductor materials. 
Keywords: Electrical resistivity, Chemical bath deposition, CdS thin films, Hall Effect. 
INTRODUCTION 
 Chemical bath deposition is a well known deposition process for Chalcogenides such 
as Cd, Zn, Co, Hg, Pb sulphides and selenides [1-2]. The Chemical Bath Deposition (CBD) 
method, being less expensive than other thin film deposition methods allows for the 
manufacture of relatively low cost devices especially light detectors, light energy conversion 
cells and thin films field effect transistor [3-5]. CdS in an important semiconductor material 
with very narrow band gap (2.10 to 2.40eV). The CdS material exhibits hexagonal structure 
with a preferred orientation along (002), (116,312) and (316,332) directions [6-9]. In this 
paper we present the results of our studies on Hall Effect of Chemical Bath Deposited CdS 
thin film. 
INTERNATIONAL JOURNAL OF PHYSICS 
 
ISSN:   (Print) 
ISSN:   (Online)  
 
Volume 1, Issue 1, January- March (2012), pp. 15-20 
© IAEME: www.iaeme.com/ijp.html 
 
 
IJP 
© I A E M E 
International Journal of Physics (IJP), Volume 1, Issue 1, January- March 2012 
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EXPERIMENT 
 A simple Chemical bath deposition (CBD) method was employed to deposit CdS thin 
films on to glass substrates using thiourea as sulfide ion source and cadmium sulphate as 
cadmium ion source in Ammonia bath. For the preparation of CdS thin films, 110ml of water 
heated upto 700c and glass substrates was inserted and 0.0623M Cadmium sulphate was 
added with slow stirring of the precipitated solution. Ammonia solution (NH3) was then 
added. When adding ammonia solution, the temperature of precipitated solution was reduced. 
Then 0.3284M Thiourea was added slowly in the solution. After adding thiourea, the 
precipitated solution became a yellowish colour which indicates the production of Cadmium 
sulfide in the precipitated solution. Time taken for the growth of the Cadmium Sulfide on the 
glass substrates varied from 30 minutes to 45 minutes [10-11]. Hall Effect Measurement 
System- 7600 Series is designed to provide totally automatic measurements of resistivity, 
mobility and carrier concentration of a wide range of samples over a temperature range from 
70K to 730K. 
RESULT AND DISCUSSION 
 Hall Effect Measurement (HMS) systems feature a moderate resistance range, high 
voltage capability, high magnetic field, and broad temperature range to provide very capable 
electronic transport measurement systems. 
 
Fig.1. Hall resistance Vs temperature for the CdS thin films of thickness 560 Å, 1180 
Å and 1700 Å 
International Journal of Physics (IJP), Volume 1, Issue 1, January- March 2012 
17 
 
  
 Figure 1. shows that,  the temperature dependencies of absolute values of Rxy / H for the 
CdS thin films of thickness 560 Å, 1180 Å and 1700 Å. At low thickness 560 Å, the zero-
field slope has strong temperature dependence.   
  
Fig.2. Hall resistances with Hall temperature for the CdS thin films of thickness  
(a) 560 Å, (b) 1180 Å and (c) 1700 Å. 
 
 
  
International Journal of Physics (IJP), Volume 1, Issue 1, January- March 2012 
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 The temperature rapidly decreases with increasing thickness of the films 1180 Å and 
1700 Å. It becomes equal to the high field slope at T ≃ 60 K. Those temperatures represent 
the cluster glass-to-paramagnetic transition in the films.  At higher thickness Rxy (H) becomes 
linear and Rxy/H is almost temperature independent, typical for the ordinary Hall effect in 
the paramagnetic state of thin films. 
 
Main panels of Fig.2. shows, −Rxy (H) at Hall temperature for the CdS thin films of 
thickness 560 Å, 1180 Å and 1700 Å. Low thickness films 560 Å show, a hysteresis at the 
lowest temperature with significant coercivity of 0.6 T, indicating the out-of-plane magnetic 
anisotropy.  It is seen, how-ever, that Rxy (H) continues to grow at large fields. This is due to a 
weak magnetism in those strongly diluted, sub-critical CdS thin films. In this case the saturable 
extraordinary Hall Effect (EHE) is of the same order as the non-saturable OHE contribution. 
With increasing thickness 1180 Å and 1700 Å, the coercivity rapidly decreases 0.16 T and 
0.06 T respectively. However, Rxy (H) remains nonlinear, curves with open circles in the main 
panels indicating presence of the residual cluster magnetism in the CdS thin films.   
Figure 3. shows, The difference of Rxy / H at low and high thickness of the CdS thin 
films of  thickness 560 Å, 1180 Å and 1700 Å,  its provides an accurate measure of 
nonlinearity of the Hall effect. The switching of Rxy at small fields is associated with the 
planar Hall Effect (PHE). The PHE appears when there is a component of magnetization in 
the film plane. The contribution from the PHE is zero when the magnetization is parallel or 
perpendicular to the current. It is zero at high thickness (1700 Å) when the sample is magnetized 
perpendicular to the current flow direction Fig. 3. (c). Note that a similar non-monotonous Rxy 
(H) is observed for the film with thickness 1180 Å Fig.3.(b) , but not observed for more diluted 
film with thickness 560 Å, as seen from Fig.3.(a).  This gain demonstrates different behavior of 
CdS thin films with low and high thickness. 
 
International Journal of Physics (IJP), Volume 1, Issue 1, January- March 2012 
19 
 
 
Fig. 3. Magnetic field dependencies of the Hall resistances for the CdS thin films of 
thickness (a) 560 Å, (b) 1180 Å and (c) 1700 Å. 
 
  
 
 
 
 
International Journal of Physics (IJP), Volume 1, Issue 1, January- March 2012 
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CONCLUSION 
 CdS thin film has been deposited on a well cleaned glass substrate by chemical 
bath deposition technique. CdS shows n-type conductivity. Carrier concentration is found to 
improve with Cd concentration in bath. Conductivity is found to improve with dosage. In all 
cases of CdS thin films saturation values of the Hall resistance decrease with decreasing 
thickness of the films because the measured signal is proportional to the out-of-plain component 
of the magnetic moment, which scales as the sine of angle. 
REFERENCES 
1. Aitchison R. F. (1951), Nature, Lond., Vol. 167, pp. 3812-3821.  
2. Ashour H., El Akkad F. (2001), Phy. Status Solidi (a)., Vol. 184, pp. 175.  
3. Borges R. O. and Lincot D. (1993), J. Electrochem. Soc., Vol. 140(12),  pp. 3464. 
4. Boudreau R.A. and Rauh R.D. (1983), J. Electrochem. Soc., Vol. 130, pp. 
513-518. 
5. Cardona P.M. (2001),  Fundamentals  of  Semiconductors:  Physics  and 
Materials Properties, Springer-Verlag, Berline, Vol. 52, pp.234-248. 
6. Carlson A. E., Shiozawa L. R. and Finegan J. D (1958), U. S. Patent, Vol 2, pp. 
820-841.  
7. Francombe H.  and Vossen J.L. (1982), Physics of Thin Films, vol, 12, pp. 
201. 
8. Francou J. M., Saminadayar K. and Pautrat J. L. (1990), Phys. Rev., B 41, 
12035.  
9. Garcia V.M., Nair M.T.S., Nair P.K. and Zingaro R.A. (1995), Semicond. 
Sci.Technol., Vol. 10, pp. 427-431. 
10. George P. J., Sanchez A., Nair P. K. and Nair M. T. S. (1995), App. Phys. 
Lett., Vol. 66(26), pp. 3624-3632.  
11. Gibson P. N., Ozsan M. E., Lincot D., Cowache P. and Summa D. (2000), Thin 
Solid Films. Vol. 34, pp. 361-362.  
 
 
*Corresponding author: kathirvelde.5@gmail.com 


HALL EFFECT OF CHEMICAL BATH DEPOSITED CdS THIN FILMS

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HALL EFFECT OF CHEMICAL BATH DEPOSITED CdS THIN FILMS

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