Rapid Atmospheric Vapor Deposition of H:In ₂ O ₃ Transparent Conducting Oxide Thin Films

Transparent conducting oxides (TCOs) are essential for the optoelectronics industry, but there is a critical gap in cost‐effective methods to rapidly deposit low‐sheet‐resistance, high‐transmittance films without damaging delicate materials, including emerging soft semiconductors like metal‐halide perovskites. In this work, atmospheric pressure chemical vapor deposition (AP‐‍CVD) is used to synthesize H:In ₂ O ₃ films with 7.20 ± 0.01 Ω □ ⁻¹ sheet resistance (0.50 ± 0.06 mΩ cm resistivity) and transmittance up to 89% in the near‐infrared (NIR), surpassing commercial sputter‐deposited indium tin oxide. The growth rate is 40 higher than atomic layer deposition (ALD), and the AP‐CVD films are fully processed under atmospheric conditions at only 140 °C. Comparison of secondary ion mass spectrometry and time‐of‐flight elastic recoil detection analysis with changes in carrier concentration indicates that H dopants are introduced from the water oxidant. There is an increase in mobility from 40 ± 10 cm ²  V ⁻¹  s ⁻¹ to 160 ± 30 cm ²  V ⁻¹  s ⁻¹ when changing from O ₂ to H ₂ O as the oxidant, which is attributed to hydrogen‐mediated passivation of defect‐related electronic states that would otherwise act as carrier scattering centers. This work establishes AP‐CVD as a promising method for manufacturing high figure‐of‐merit TCOs in a rapid, scalable, and cost‐effective manner, using mild growth conditions compatible with thermally‐sensitive materials.