Silver oxide-mediated synergistic enhancement of conductivity and adhesion in low-temperature cured silver pastes

Enhancing the conductivity of silver paste is crucial for achieving high photoelectric conversion efficiency of heterojunction solar cells. In this work, 1-tetradecanol-coated Ag2O was used as a silver precursor, replacing nano-silver powder in the conventional silver paste. Low-temperature sintering (200 °C) was utilized to establish a conductive pathway between flaky and spherical silver powder, resulting in a low-cost, low-temperature cured silver paste. The effect of 1-tetradecanol content on Ag2O was investigated, focusing on the electrical conductivity, silver paste rheological properties and adhesion properties of low-temperature cured silver paste film layers. The results showed that the volume resistivity of the paste containing 1-tetradecanol (10 wt%)-coated Ag2O after sintering at 200 °C for 30 min was 7.44 × 10−5 Ω cm, which was 35% lower than that of pure silver powder paste, indicating a significant enhancement in electrical conductivity. Furthermore, rheological performance tests demonstrated that the incorporation of Ag2O was an effective route for enhancing the thixotropy, recovery, and stability of the paste. Meanwhile, an adhesion experiment demonstrated that silver pastes with introduced Ag2O (≥5 wt%) exhibited a robust bonding to the ITO substrate under low-temperature curing, with an ASTM grade of 5B.