ALD grown zinc oxide with controllable electrical properties

TL;DR

This study investigates low-temperature ALD-grown zinc oxide films, revealing their electrical properties and suitability for flexible electronic devices due to controllable free carrier concentration and high rectification ratios.

Contribution

It demonstrates that low-temperature ALD can produce high-quality ZnO films with tunable electrical properties suitable for flexible electronics and junction applications.

Findings

Free carrier concentration as low as 10^15 cm-3

Electron mobility between 20 and 50 cm2/Vs

High rectification ratio in ZnO-based junctions

Abstract

The paper presents results for zinc oxide films grown at low temperature regime by Atomic Layer Deposition (ALD). We discuss electrical properties of such films and show that low temperature deposition results in oxygen-rich ZnO layers in which free carrier concentration is very low. For optimized ALD process it can reach the level of 10^15 cm-3, while mobility of electrons is between 20 and 50 cm2/Vs. Electrical parameters of ZnO films deposited by ALD at low temperature regime are appropriate for constructing of the ZnO-based p-n and Schottky junctions. We demonstrate that such junctions are characterized by the rectification ratio high enough to fulfill requirements of 3D memories and are deposited at temperature 100degC which makes them appropriate for deposition on organic substrates.