Analysis of Mono-cast Silicon Wafers and Solar Cells on Industrial Scale

Mono-cast silicon recently became available in volumes relevant for industrial scale production of solar cells. At the present time, mono-cast wafers are classified by an optical determination of the <100>-grain area on the wafer. This paper discusses solar cell efficiency distributions of mono-cast wafers which we obtained in first tests using an industrial cell process. A screening process based on the optical classification turns out to be insufficient in order to obtain a narrow efficiency distribution. We used photoluminescence imaging as an additional fast inspection tool for wafers and solar cells. Prominent defects of mono-cast wafers were investigated using photoluminescence, electroluminescence and reverse biased electroluminescence (ReBEL) imaging as well as the structural defect density (SDD) method on a laboratory scale.