Room Temperature Pulsed Laser Deposition of Aluminum Zinc Oxide (AZO): Enabling Scalable Indium-Free Transparent Conductive Oxides

Abstract

Indium tin oxide (ITO) is the leading transparent electrode material in displays and in photovoltaics. As both these markets are vast and rapidly expanding, the demand for alternative transparent conductive oxides (TCOs) is becoming increasingly urgent due to the limited availability of indium. Herein, aluminum-doped zinc oxide (AZO) is revisited as a promising indium-free TCO candidate. An industrial-scale pulsed laser deposition (PLD) process is developed that produces highly conductive and transparent AZO films at room temperature, without the need for post-deposition annealing. This PLD-AZO films have excellent morphological, electrical, and optical properties, with sheet resistances of ≈ 55–25 Ω ϒ⁻¹ for thin TCO thicknesses (around 100 to 200 nm, respectively), and absorptance from 400 to 1000 nm below 10%. We demonstrate the application of this highly conductive PLD-AZO not only as a bottom contact but also as an effective top contact in perovskite solar cells, highlighting its versatility. The AZO-based devices achieve performance and stabilities equivalent to that of ITO-based. This findings demonstrate the robustness and potential of PLD-deposited AZO layers in enhancing displays and PV production and facilitating the wider adoption of renewable and sustainable TCO alternatives in the expanding photovoltaics and displays markets.