Analysis of very thin high-efficiency solar cells

Recent experimental results of inverted pyramids passivated emitter and rear cells (IP-PERC) of varying thickness down to 63 /spl mu/m on FZ and Cz material are presented. The rear side contacts are made conventionally as well as by the laser-fired contacts (LFC) method. The V/sub oc/ dependence on cell thickness of annealed and degraded Cz is measured. The investigated relationships can be modeled well by PC1D. Thus it is possible to predict the cell performance depending on thickness and bulk diffusion length. The wafers were thinned down from 250 /spl mu/m with new equipment (fully automatic infeed grinder) at Fraunhofer ISE labs.