Simplified buried contact solar cell process

The buried contact solar cell (BCSC) was originally developed as a high performance technology capable of taking full advantage of the high voltages and efficiencies able to be achieved with floatzone substrates. In this process, three lengthy high temperature processes are necessary. In recent months, a simplified process has been developed that eliminates these three lengthy high temperature processes associated with groove diffusion, back surface field formation and the growth of a thick thermal oxide on the surface. Although considerable performance loss is sustained when applied to floatzone substrates, the simplified process appears capable of achieving similar efficiencies to the conventional BCSC process when applied to solar grade Czochralski and multicrystalline substrates. Just as importantly, the simplified BCSC process has been developed for implementation onto existing screen printing production lines using virtually all the same equipment except for the addition of the grooving process which is applied to the virgin wafer prior to any other processing. This process appears to be particularly well suited to existing manufacturers of screen printed solar cells, where the higher performance and lower cost of the BCSC can be achieved without the need for the decommissioning of existing equipment or large scale investment in new infrastructure and equipment.