Indium tin oxide thin films for organic light-emitting devices

TLDR

The study used room‑temperature PLD‑grown ITO films to evaluate the electroluminescence performance of organic light‑emitting devices. High‑quality 150–200 nm ITO films were deposited on glass by pulsed laser deposition without post‑annealing, and their electrical, optical, and structural properties were examined as functions of substrate temperature, oxygen pressure, and thickness. The films exhibited ≥85 % transparency, 2–4 × 10⁻⁴ Ω cm resistivity, 29 cm² V⁻¹ s⁻¹ mobility, ~5 Å surface roughness, and delivered electroluminescence comparable to commercial ITO anodes.

Abstract

High-quality indium tin oxide (ITO) thin films (150–200 nm) were grown on glass substrates by pulsed laser deposition (PLD) without postdeposition annealing. The electrical, optical, and structural properties of these films were investigated as a function of substrate temperature, oxygen pressure, and film thickness. PLD provides very uniform ITO films with high transparency (⩾85% in 400–700 nm spectrum) and low electrical resistivity (2–4×10−4 Ω cm). The Hall mobility and carrier density for a 170-nm-thick film deposited at 300 °C are 29 cm2/V s and 1.45×1021 cm−3, respectively. Atomic force microscopy measurements of the ITO films indicated that their root-mean-square surface roughness (∼5 Å) is superior to that (∼40 Å) of commercially available ITO films deposited by sputtering. ITO films grown at room temperature by PLD were used to study the electroluminescence (EL) performance of organic light-emitting devices. The EL performance was comparable to that measured with commercial ITO anodes.