Investigation of the P-doped lead-free glass frit based on the principle of low-temperature phosphorus diffusion for multicrystalline silicon solar cells

Abstract

For P-doped glass frits, the doping efficiency of phosphorus is low because of the volatility of phosphorus at high temperatures. A lead-free 5% P-doped glass frit was prepared using low-temperature phosphorus diffusion. The network structure formed by the glass was mainly composed of [BiO6] octahedron, [SiO4] tetrahedron, and [BO4] tetrahedron. The pore size of the glass frit was distributed in the mesopore range. High-temperature microscopy confirmed that the glass frit began to soften at 620 °C. The glass frit was prepared into a front silver paste for multicrystalline silicon solar cells. The high efficiency of P2O5 doping helped resolve problematic defects caused by the typically poor doping efficiency of P-doping while forming the n-type emitter and p-n junction of solar cell. Finally, the solar cell photovoltaic conversion efficiency improved to 18.3%.