Effect of Pb-Te-Si-O glasses on Ag thick-film contact in crystalline silicon solar cells

Abstract In the paper, the influences of Pb-Te-Si-O (PTSO) glasses on Ag thick-film contact in crystalline silicon solar cells were investigated. Thermal properties of PTSO glasses and the dissolution process of Ag were studied. The formation of a new low-softening-temperature glassy-phase, induced by the crystallization of PTSO-1 glass, accelerated the dissolution of Ag at lower temperature. When silver paste was sintered, high-viscosity PTS-1 glass could flow to the surface of the cell and etch SiN x ARC layer at relative high temperature and the time for etching through SiN x ARC layer was shorter. Viscosity-temperature properties of PTSO glass has played a great role in the microstructures of contact finger and Ag/Si interface and have a great effect on the quality of Ag/Si contact and electrical properties of cells by affecting the sintering process of Ag, the etching behavior of interfacial glass with SiN x and Si, and the size and size distribution of Ag crystallites grown into the Si emitter at the position of inverted-pyramid etching pits.