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

Abstract

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.