Learning to appreciate the maxim “less is more”

We present the profound performance enhancements experienced when an ultra-thin nanocrystalline silicon (nc-Si) film is utilized in our light and carrier collection management (LCCM) architecture (US Patent 8,294,025). We begin by establishing theoretical short circuit current density (J_sc) values for planar nc-Si devices. Numerical simulation results for the same thicknesses conformally coated over nano-element arrays are then given. J_sc values above 30mA/cm² are shown for the nc-Si LCCM cells for nc-Si films as thin as 200nm. To attain a J_sc of 35.5mA/cm², the LCCM solar cell architecture reduces the required nc-Si volume by 98.3% compared to the planar solar cell that would match that performance. The minimization of material while maximizing performance has obvious implications for cost/watt savings. The architectural dimensions that are the product of this study are invaluable for cell manufacturing.