Glucose Treatment Enhances Nickel Electrode Quality in Silicon Heterojunction Cells: Experiments and Theoretical Calculations

In the photovoltaic industry, silver paste screen printing is the mainstream metallization technology for crystalline silicon solar cells, but it is hindered by high production costs, particularly when preparing silicon heterojunction cells (SHJ) with low-temperature silver paste. To reduce these costs, electroless plating and electrodeposition technologies as alternatives for silver paste in metal electrode fabrication have gained significant attention. However, achieving a reliable interfacial contact between the metal grid and the transparent conductive oxide (TCO) on the SHJ surface remains a major challenge. This study researched the surface modification of the ITO substrate by introducing glucose molecules to enhance the coating quality of the nickel (Ni) seed layer. The results show that glucose treatment improves the wettability and reduces the roughness of the ITO surface, promoting uniform deposition of the Ni layer, which results in better adhesion and densification. DFT calculation of glucose molecule adsorption also shows that it primarily adsorbs on the ITO surface via its hydroxyl groups (–OH), modulating the surface properties. The modified Ni seed layer shows reduced resistivity, improved Fill Factor (FF = 52.63%), and photoelectric conversion efficiency (PCE = 12.04%), with increases of 5.63% and 0.93% (compared to the control), respectively. Although the PCE is slightly lower than commercial cells, the absence of silver significantly lowers production costs. Thus, glucose modification of the ITO surface effectively enhances electrode contact quality.