Towards fabrication of low cost high efficiency c-Si solar cells: Progress and optimization using TCAD simulation study

Progress of experimental and simulation work, in optimizing baseline processes for low cost, high efficiency c-Si solar cells is presented. Phosphorous diffusion at 890 °C for 15 minutes was optimized to a obtain sheet resistance of 30 Ω/□ for selective emitter region. Active area of the cell, excluding areas of front metal contact grid, was selectively etched back to obtain emitter sheet resistance of 90 Ω/□ for lightly doped emitter. Optimization of Boron diffusion for N-type solar cells was attempted. Particularly, the material properties of boron rich layer are being explored to arrive at low cost means of removing this dead layer rather than the conventional low temperature furnace processing. An initial cell (without texturing), incorporating some of these process steps resulted in 13.1% efficiency. To understand various losses and improve the efficiency further, Sentaurus TCAD simulation study was initiated.