Transport analysis for polycrystalline silicon solar cells on glass substrates

The authors fabricate polycrystalline silicon solar cells on glass by Si deposition on solid phase crystallized seed layers and derive an effective diffusion length L/sub eff,QE/=3 /spl mu/m from quantum efficiency measurements. Three-dimensional transport modeling reveals that L/sub eff,QE/ differs from the diffusion length L/sub eff,IV/ in the diode saturation current j/sub o/=(q n/sub i//sup 2/D)/(N/sub A/ L/sub eff,IV/). Here q, n/sub i/, D, and N/sub A/ denote the elementary charge, intrinsic carrier concentration, diffusion constant and doping concentration, respectively. However, the difference is small for their polycrystalline Si solar cells. Dominant recombination in the space charge region limits the open circuit voltage to 340 mV.