Study of stability of MIS polycrystalline silicon solar cells by Auger electron spectroscopy

Auger electron spectroscopy and ion sputtering techniques were used to investigate the free surface composition and MIS solar cell fabricated on polycrystalline silicon. A layer of ∠20 Å of mixture of silicon oxide and chemisorpted oxygen atoms were found on the Si surface. For the Cr–Cu–Cr–SiO₂–Si solar cell, the copper layer is the key factor for reducing the series resistance of the metal layers. The pure oxide layer was found to be almost nonexistant and a mixture of silicon oxygen and chromium was detected between the silicon and metal interface. Compositions of the cell were investigated as a function of temperature. The results were used to estimate the lifetime of the cell. It was found that the cell should have a very long lifetime if operated under 200°C.