Development and characterization of p-type PERT solar cells

This thesis presents the development and characterization of p-type PERT solar cells. To ensure industrial feasibility, a fabrication process for PERT solar cells using state-of-the-art production equipment is developed that enables a high synergy with the PERC mainstream technology. To reach this, a POCl3-based co-diffusion process together with a pre-deposited BSG layer using APCVD is developed. The introduction of the BSF in the PERC architecture resulting in the PERT structure reveals a tradeoff between increased recombination losses and reduced series resistance due to enhanced lateral conductivity, which opens interesting scientific questions. The formation of the BSF is investigated in details by the characterization of the doping profile and carrier recombination of the BSF in dependence of the diffusion process conditions. Moreover, the effect of the BSF concerning increased lateral conductivity on the rear side of the cell is considered. Therefore, analytical models for the description of the internal resistance of PERT solar cells for the non-illuminated as well as the illuminated case are developed and verified by experiment and simulation with excellent agreement.