J. Comp. & Math. Sci. Vol.3 (3), 294-296 (2012)
Electrical Properties of TCO Thin Film and Nano Solar Cells S. SAKTHIVEL1 and D.MANGALARAJ2 1
Thin film Physics and Nano Science Laboratory, P. G. & Research Department of Physics, Rajah Serfoji Govt. College, Thanjavur-613 05, Tamilnadu, INDIA. 2 Department of Nano Science and Nano Technology, Bharathiar University, Coimbatore-641 046, Tamilnadu, INDIA. (Received on: May 5, 2012) ABSTRACT Electrical properties of transparent conducting oxide (TCO) thin film used for fabricating solar cell measurement of sheet resistence (Rs) and resistivity (ρ) by four probe and square probe method for various thickness. Computer programming language C used for calculating Rs and ρ for more number of thin film and nano materials used for samples. Keywords: Sheet resistance and Resistivity.
INTRODUCTION Present day human society facing lot of problems. One of the most important problem is power production with green energy technology. Green energy in the sense energy produced from wind , tidal waves, solar energy etc. Among these solar energy is important source for producing energy . Initially we used Si wafer for fabricating solar cell then thin film technology were used for fabricating solar cell. Thin film is referred to “ random nucleation and growth process of
individually condensing/ reacting atomic/ionic/ molecular species on a substrate” Chopra K.L. et. al.1 The cost of the thin film module four to five times less than that of the Si wafer solar cell technology. Thin film of cadmium oxide , zinc oxide, tin oxide, indium tin oxide (ITO), etc are known as transparent conducting oxides (TCO). These TCO’s are playing major role in thin film solar cell fabrication. Either substrate structure or superstrate structure light trapping taking place by transparent conducting oxides only. The considerable theoretical and experimental investigations on the optical behaviour of thin films deal
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S. Sakthivel, et al., J. Comp. & Math. Sci. Vol.3 (3), 294-296 (2012)
with optical reflection, transmission and absorption properties and their relation to the optical constants of films. As a result of these studies complex multilayer optical device systems with remarkable reflection , antireflection , interference and polarization properties emerged for laboratory and industrial application. A good deal of the information in this paper has been obtained from the various articles and treatises on the optical properties of thin film. Choosing Solar cells because of large variety of deposition techniques available in relation to photovoltaic(PV) technology. The microstructural features of the absorber layer sensitively influence the PV performance of a Solar cells. Even we have different technology for fabricating solar cell, we are not able to produce efficiency not more than that of 20 %. But it is possible to produce more than 50% using mutijunction solar cell (Cost wise more) . Present work deals with the very important parameters called sheet resistance and resistivity of the transparent conducting thin film by four probe and square probe technique. Understanding and calculating the values of Rs for more number of samples computer programming â&#x20AC;&#x2DC;Câ&#x20AC;&#x2122; language were used. different films coated on different substrates and its corresponding change of resistivity and sheet resistance. For speedy computational analysis of a single film on four different substrates as well as more number of films (with different films thickness) on various types of substrate Sakthivel et al.2. SHEET RESISTANCE #include<stdio.h>
#include<conio.h> #include<math.h> void main() { float a,d,r; /* a = rho */ clrscr(); printf("Enter the value of d and r : \n"); scanf("%f%f",&d,&r); a=d*r; printf("The Rho value is = %f",a); getch(); } FOUR PROBE METHOD IN LINE #include<stdio.h> #include<conio.h> #include<math.h> void main() { float a,v,i,s; clrscr(); printf("Enter the value of v,i and s : \n"); scanf("%f%f%f",&v,&i,&s); a=(v/i)*2*3.14*s; printf("The Rho value is = %f",a); getch(); } RESISTIVITY BY METHOD
FOUR PROBE
#include<stdio.h> #include<conio.h> #include<math.h> void main() { float r,v,i; clrscr(); printf("Enter the value of v,i : \n");
Journal of Computer and Mathematical Sciences Vol. 3, Issue 3, 30 June, 2012 Pages (248-421)
S. Sakthivel, et al., J. Comp. & Math. Sci. Vol.3 (3), 294-296 (2012)
scanf("%f%f%",&v,&i); r=4.532*(v/i); printf("The r value is = %f",r); getch(); } RESISTIVITY BY METHOD
SQUARE PROBE
#include<stdio.h> #include<conio.h> #include<math.h> void main() { float r,v,i; clrscr(); printf("Enter the value of v,i : \n"); scanf("%f%f%",&v,&i); r=9.06*(v/i); printf("The r value is = %f",r); getch(); }
decrease in the transmittance , TCO should be stable in superstrate structure during solar cell fabrication. CONCLUSION Properties of transparent conducting oxide thinfilm prepared by spray pyrolysis and sputtering technique and its sheet resistance and resistivity were measured by four and square probe technique Using ‘C’ language programs. The values of Rs and ρ should be always less than 10 for ITO, ZnO: B, ZnO:Al and SnO2:F transparent conducting oxide thin film (C. S. Solanki et al.). REFERENCES 1.
2. RESULT AND DISCUSSION Resistivity of the TCO film is a very important parameters it should be as low as possible for example 1/10 Ώ per □. The resistivity affects the design and cost of the solar cell. For minimizing the resistive loss the current flowing through the TCOshould be carefully measured. Transmittance and electrical conductivity of the TCO should be as high as possible. The refractive index and thickness of the TCO related with d x n = λ/4 wavelength
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Chopra,K.L., Pauison, P.D. and Dutta,V “ Thin Film solar cells: Progress in Photovoltaics Research and Applications” Vol. , 12, P 69, (2004). Sakthivel. S, Selleswari. G.T.C, Narayandass. Sa. K, Mangalaraj. D, National Workshop on Thin Film Preparation and Characterization Tehniques for energy Conversion, Nov. 22-26, (2004.) R. Sathyamoorthy, Narayandass. Sa. K, Mangalaraj. D, Solar Energy Materials and Solar Cells, 76,339-346 (2003). C. S. Solanki, Solar Photovoltaic, Fundamentals, Techniques and Applications, Second Edition July (2011).
Journal of Computer and Mathematical Sciences Vol. 3, Issue 3, 30 June, 2012 Pages (248-421)