Evaluation of temperature dependent stress around electrodes in crystalline silicon solar cells by Raman spectroscopy

Abstract This study investigates the impact of temperature on the reliability of crystalline silicon solar cells, focusing on thermal expansion mismatches. Thermal stress behavior in Si hetero-junction solar cells with textured surfaces, Ag paste electrodes, and low-melting-point solder for ribbon adhesion was analyzed using temperature-variable Raman spectroscopy. Raman shifts indicated the induction of compressive stress at high temperatures and tensile stress at low temperatures. Apparent trends change in the stress were observed above 160 °C due to solder softening/melting. These stresses increased the risk of crack formation during thermal cycling, such as Japan Automobile Standards Organization (JASO) standard test for vehicle parts, particularly in the vicinity of busbar with soldered. This study emphasizes the effectiveness of stress evaluation using temperature-variable Raman spectroscopy. It also points out the need for optimized designs to improve mechanical durability and overall performance under harsh thermal environmental conditions.