Rapid Atmospheric Vapor Deposition of H:In2O3 Transparent Conducting Oxide Thin Films

TL;DR

This paper demonstrates a rapid, scalable atmospheric pressure chemical vapor deposition method to produce high-quality H:In2O3 transparent conducting oxide films with superior properties at low temperatures.

Contribution

It introduces a novel AP-CVD process for synthesizing high-performance TCO films efficiently and under mild conditions, surpassing existing deposition techniques.

Findings

Achieved low sheet resistance of 7.20 Ohm/sq with 89% transmittance.

Growth rate is 40 times higher than atomic layer deposition.

H dopants from water oxidant improve carrier mobility from 40 to 160 cm²/Vs.

Abstract

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 synthesise H:In2O3 films with 7.20+/-0.01 Ohm/sq sheet resistance (0.50+/-0.06 mOhm.cm resistivity) and transmittance up to 89% in the near-infrared (NIR), surpassing commercial sputter-deposited indium tin oxide. The growth rate is 40x 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 indicate that H dopants are introduced from the water oxidant. There is an increase in mobility form 40+/-10 cm2/Vs to 160+/-30 cm2/Vs when changing from O2 to H2O as the oxidant, which is attributed to H dopants passivating oxygen vacancies that 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.