THIN MONOCRYSTALLINE SI SOLAR CELLS FABRICATED BY THE POROUS SI (PSI) PROCESS USING ION ASSISTED DEPOSITION

We fabricate monocrystalline silicon solar cells grown on non-textured porous silicon by ion assisted deposition. The 7-µm-thick epitaxial silicon layer is transferred to a glass substrate. The cell exhibits an open circuit voltage of 501 mV, a short circuit current of 14.6 mA/cm2, a fill factor of 0.60, and an energy conversion efficiency of 4.4 %. The quantum efficiency reveals a minority carrier diffusion length of 3 µm. From this diffusion length and the ideality factor n = 2 that is extracted from the current-voltage curve and from the temperature dependence of the diode saturation current, we conclude that recombination losses in the space charge region dominate.