Enhanced phosphorus gettering of impurities in p-type Czochralski silicon through a variable temperature processing (VTP)

• The solar cell efficiency is depends to the distribution of metals within the silicon bulk.
• Variable temperature process is a tool to optimize the mechanisms of gettering.
• There is a critical temperature which the gettering efficiency attained their optimum.

This paper investigates the effect of heat treatment with a phosphorus-rich porous silicon layer on the electrical properties Czochralski (CZ), p-type monocrystalline silicon (c-Si) wafer. Phosphorus diffusion into porous silicon layer can play a crucial role for gettering metallic impurities. Further, the variable temperature process (VTP) was presented to provide higher gettering efficiency than the constant temperature process (CTP). We estimated with a Quasi-Steady-State Photo-Conductance (QSSPC) technique the effective minority carrier lifetime values τeff. The Light-Beam-Induced-Current measurements (LBIC) have been executed to estimate the diffusion length (LD). In the I–V characteristics, we observed a significant increase in Voc and Jsc. Particularly; we can say that the VTP may be required to provide the highest efficiency in devices.