Abstract: Highly reflective glaze is commonly applied to solar photovoltaic glass to improve photovoltaic conversion efficiency. However, their impact on the fracture strength of solar photovoltaic glass remains inadequately understood. This study quantitatively investigated the effects of thickness (1.55, 1.86 and 2.89 mm), glaze type (A and B), loading rate (2, 20, 50 mm/min) and upper indenter force surfaces (glaze and glass) on the fracture strength of solar photovoltaic glass using the ring-on-ring test and the four-point bending test. The results were analyzed using the Weibull distribution. The results show that both types of reflective glaze significantly diminish the fracture strength of solar photovoltaic glass. The ring-on-ring test, which involves contact with the back side of the glaze, demonstrates a remarkable reduction in fracture strength, exceeding 72%, surpassing the reduction observed in the four-point bending strength (26%~46%). Furthermore, a substantial decrease in fracture strength is observed with decreasing glass thickness. For instance, the fracture strength of 2.89 mm fully tempered solar photovoltaic glass with glaze in the four-point bending test measures approximately 104 MPa, whereas the fracture strength of 1.55 and 1.86 mm semi-tempered solar photovoltaic glass is only about 68 and 73 MPa. Scanning electron microscopy images reveal that the primary cause of the reduction in fracture strength of solar photovoltaic glass is the presence of defects, such as micropores in the glaze layer and the solar photovoltaic glass substrate.

Key words: solar photovoltaic glass, highly reflective glaze, thickness, fracture strength, Weibull distribution, four-point bending