Effect of rare metal oxide doped lead-based glass frits on the performance of crystalline silicon solar cells

：Based on the study of traditional lead-based glass frit systems, in this work, melt-quenching method was used to prepare a type of rare metal oxide-doped glass frit. The influence of the composition of glass frit on the softening temperature of the glass frit, the cross-sectional structure, the surface morphology of the front electrode grid line of the solar cell, the contact interface structure, and the electrical properties of the solar cell were studied by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive X-ray Spectroscopy (EDS), High stage microscope (HSM), X-ray photoelectron spectroscopy (XPS) and Differential Scanning Calorimeter (DSC). The results indicated that the characteristic temperature points of the glass frits doped with metal oxides were superior to those of traditional glass frits. In addition, the glass frits doped with both metal oxides could be completely melted at approximately 626 °C. When glass frits were introduced into the grid line of the front electrode for a solar cell, the silver powder could dissolve and etch the anti-reflection film, forming a thin glass layer containing a large number of silver crystals and an Ag–Pb eutectic alloy at the Ag–Si contact interface. This provided an effective approach for electronic transmission, thereby promoting the formation of good ohmic contact. Consequently, compared with the solar cells made of traditional glass frit, the monocrystalline silicon solar cells composed of glass frit doped with rare metal oxides had a lower series resistance value (2.41 mΩ) and higher photoelectric conversion efficiency (22.62%).