Thin SolidFilms, 97(1982) 47-51 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIH PREPARATION AND CHARACTERIZATION 47 PREPARATION OF (THIN FILM SnO,)/(TEXTURED n-Si) SOLAR CELLS BY SPRAY PYROLYSIS F. J. GARCiA AND J. MUCI Departamento de Eiectrbnica y Circuitos, Universidad Simdn Bolivar, Caracas (Venezuela) M. S. TOMAR Departamento de Fisica, Universidad Simdn Bolivar, Caracas (Venezuela) (Received October 15,198l; accepted April 3,1982) Semiconductor/insulator/semiconductor solar cells were prepared by the spray pyrolysis of fluorine-doped tin oxide over textured n-type single-crystal silicon. The photogenerated current of these cells was compared with that produced by similar cells fabricated over silicon with a polished surface. The textured cells consistently showed higher currents than the polished cells. This rise in photocurrent, together with the observed improvement in the spectral response over a wide range of wavelengths, indicates an increase in the collection efficiency of the cells. It is suggested that the incorporation of this feature can enhance the performance of this type of cell. 1. INTRODUCTION Semiconductor/insulator/semiconductor (SIS) cells consisting of a wide gap semiconductor (window) over a smaller gap semiconductor (absorber) and generally incorporating a thin insulating interfacial layer represent an alternative for reducing the overall cost of solar cells. If the top semiconductor has a band gap such that it is transparent for most of the solar spectrum, the incident photons can reach the junction without being absorbed. Since the absorption coefficient of the absorber semiconductor is high at photon energies considerably above the semiconductor’s band gap, the low wavelength photons are absorbed near the surface of the absorber semiconductor, in the region of the built-in field. Here the collection efficiency is high and the effect of the surface recombination velocity is greatly reduced by the presence of this field. As a consequence, the short wavelength spectral response of SIS cells will be in general better than that in a corresponding diffused junction cell. Although diffused shallow junction cells with a treated front surface have improved the short wavelength collection efficiency and reduced the effect of the front surface recombination, an SIS structure can achieve this in a simpler and less expensive way. Wide band gap oxide semiconductors such as indium-tin oxide (ITO), tin oxide, zinc oxide, cadmium oxide etc. can be used conveniently as the top window semiconductor of an SIS cell. These oxides can be deposited over an absorber semiconductor in the form of thin films of high electrical conductivity and high optical transmission for most of the solar spectrum. They can simultaneously 0040-6090/82/0000-0000/$02.75 0 Elsevier Sequoia/Printed in The Netherlands