Measurements of back reflectivity from IQE of Al back field silicon solar cells

Abstract

This paper gives a method of measuring reflectivity of Al back surface field of solar cells. A simple model of Al back field silicon solar cells has been used to explain their IQE. It is found that IQE at the range of near band-gap wavelengths is sensitive to the back surface reflectivity. At the near-bandgap wavelengths, the optical effects play an important role. It is also concluded that back reflectivity of Al back field can be determined by fitting the IQE curve at the range of near band gap wavelength with the help of this model. This method can easily measure the reflectivity of Al back surface field indirectly, and analyze the effectively of the screen print technology. So this paper solves the difficulty of the measurement of the back reflectivity of Al back field, and gives a big help to the analysis of screen print technology.