Department of Adaptive Machine Systems, Graduate School of Engineering, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
Langmuir. 2013 Sep 3;29(35):11192-7. doi: 10.1021/la402026r. Epub 2013 Aug 20.
We formulate copper salt (copper formate/acetate/oleate) precursor inks for photonic sintering using high-intensity pulsed light (HIPL) based on the ink's light absorption ability. The inks can be developed through controllable crystal field splitting states (i.e., the ligand weights and their coordination around the metal centers). The inks' light absorption properties are extremely sensitive to the carbon chain lengths of the ligands, and the ink colors can drastically change. From the relationship between the ratios of C/Cu and the required sintering energies, it is possible to ascertain that the integral absorbance coefficients are strongly correlated with the photonic sintering behavior. These results suggest that the ink absorbance properties are the most important factors in photosintering. The wires formed by sintered copper formate complex ink via the HIPL method showed good electronic conduction, achieving a low resistivity of 5.6 × 10(-5) Ω cm. However, the resistivity of the wires increased with increasing contains carbon chain length of the inks, suggesting that large amounts of residual carbon have negative effects on both the wire's surface morphology and the electrical conductivity. We find in this study that high light absorptivity and low carbon inks would lead to a lower environmental load in future by reducing both energy usage and carbon oxide gas emissions.
我们采用高强度脉冲光（HIPL）基于墨水的光吸收能力来制定用于光子烧结的铜盐（甲酸铜/乙酸铜/油酸铜）前体墨水。这些墨水可以通过可控的晶体场分裂状态（即配体的重量及其在金属中心周围的配位）来开发。墨水的光吸收特性对配体的碳链长度极其敏感，墨水颜色会发生明显变化。从 C/Cu 比值与所需烧结能量之间的关系可以确定，积分吸收系数与光子烧结行为密切相关。这些结果表明，墨水的吸收特性是光固化的最重要因素。通过 HIPL 方法烧结甲酸铜络合物墨水形成的线材具有良好的导电性，实现了低电阻率 5.6×10(-5) Ω cm。然而，线材的电阻率随墨水碳链长度的增加而增加，表明大量残留的碳对线材的表面形貌和导电性都有负面影响。我们在这项研究中发现，高吸光率和低碳含量的墨水将通过减少能源使用和二氧化碳气体排放，从而在未来降低环境负荷。
