Comparative Analysis of Si PERT Cells with n+-p-p+ and n+-n-p+ Structures

Two sets of bifacial n
⁺
-p-p
⁺
and n
⁺
-n-p
⁺
solar cells were fabricated using single-crystalline Cz Si. The cells of both sets have identical n
⁺
-layers with a sheet resistance, R
sh
of 85 $\Omega /\square $. In the same time the p
⁺
-layers of the cells of the each set differ in B doping levels: R
sh
are 140 and 45 $\Omega /\square $. While implied V
oc
of the contactless structure tends to increase with increasing R
sh
, the effective velocity of the back surface recombination, S
eff
, in complete n
⁺
-p-p
⁺
cell is contrariwise depending of R
sh
. The last statement is based on the analysis of the measurements of spectral IQE of the cells.