A Study on the Effect of Various Initiators of Acrylic Binder for Low-Temperature Curing Silver Paste

In heterojunction (HJT) solar cells, an amorphous silicon passivation layer is attached to the top and bottom of a crystalline silicon layer. HJT solar cells are manufactured at approximately 200°C because the structure of amorphous Si:H changes at high temperatures. Therefore, the silver paste utilized as an electrode on HJT solar cells should be subsequently cured at low temperatures below 200°C. In addition, the electrode requires good conductivity even at low curing temperatures. An initiator in the binder is crucial for the production of silver paste capable of low-temperature curing. This study investigated the effects of various initiators on the characteristics of a binder and silver paste that can be cured at low temperatures. Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were operated to investigate the initiation and thermal decomposition properties of binders. The relationship between gel contents and the electrical conductivity of cured pastes was explored to reveal the impact of the curing ratio on electrical conductivity. The appropriate utilization of the initiator resulted in a high curing rate, which in turn increased the electrical conductivity.