Two theoretical equations concerning the grain boundary recombination velocity and the grain diffusion length were derived on the basis of an idealized tow-dimensional model for polycrystalline Si solar cell with predominantly columnar orientation.
To evaluate the model, experiments were carried out polycrystalline Si solar cells using Light-Beam-Induced-Current(LBIC) technique. The diffusion length and the grain boundary recombination velocity were found to be 5-13μm and 4-50x$10^3$cm/sec respectively.
In addition, using a lock-in amplifier and filters, four experimental curves were obtained as a function of the light beam intensity.
The results showed that the recombination velocity appeared to increase slightly as the light beam intensity decreased.
