Si-doped zinc oxide transparent conducting oxides; nanoparticle optimisation, scale-up and thin film deposition

Silicon-doped zinc oxide, Zn1−xSixOy, transparent conducting oxide nanoparticles were prepared using a laboratory scale (production rate of 60 g h−1) continuous hydrothermal flow synthesis (CHFS) process in the dopant range 0.25 to 3.0 at% Si. The resistivity of the materials was assessed as pressed heat-treated pellets, revealing that the sample with the lowest resistivity (3.5 × 10−2 Ω cm) was the 0.25 at% Si doped ZnO sample. The synthesis of this optimum composition was then scaled up to 350 g h−1 using a larger pilot plant CHFS process. Spin coating of a slurry of the resulting nanopowder made on the pilot plant, followed by an appropriate heat-treatment, produced a thin film with an optical transmission >80% and a low resistivity of 2.4 × 10−3 Ω cm, with a carrier concentration of 1.02 × 1020 cm−3 and a mobility of 11 cm2 V−1 s−1. This is a factor of almost twenty times improvement in the resistivity versus the analogous pressed, heat-treated pellet.

采用实验室规模（生产率为60克/小时）的连续水热流合成（CHFS）工艺，在硅掺杂量为0.25 - 3.0原子%的范围内制备了硅掺杂氧化锌（Zn₁₋ₓSiₓOᵧ）透明导电氧化物纳米粒子。将材料压制成型并进行热处理后制成颗粒，对其电阻率进行评估，结果表明电阻率最低（3.5×10⁻²Ω·cm）的样品是硅掺杂量为0.25原子%的氧化锌样品。然后，使用更大的中试规模CHFS工艺将这种最佳成分的合成规模扩大到350克/小时。将中试工厂制备的所得纳米粉末制成浆料，通过旋涂，然后进行适当的热处理，制得的薄膜透光率>80%，电阻率低至2.4×10⁻³Ω·cm，载流子浓度为1.02×10²⁰cm⁻³，迁移率为11cm²·V⁻¹·s⁻¹。与类似的压制、热处理颗粒相比，其电阻率提高了近20倍。