The Influence of Oxygen Flow Ratio on the Optoelectronic Properties of p-Type Ni1−xO Films Deposited by Ion Beam Assisted Sputtering

In this work, p-type non-stoichiometric Ni1−xO thin films were deposited by oxygen ion beam assisted RF sputtering on glass substrates. The influence of the oxygen flow ratio (0–100%) on the films’ optoelectronic properties was investigated. In our experimental conditio...

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Bibliographic Details
Main Authors: Hui Sun, Sheng-Chi Chen, Wen-Chi Peng, Chao-Kuang Wen, Xin Wang, Tung-Han Chuang
Format: Article
Language:English
Published: MDPI AG 2018-04-01
Series:Coatings
Subjects:
Online Access:http://www.mdpi.com/2079-6412/8/5/168
Description
Summary:In this work, p-type non-stoichiometric Ni1−xO thin films were deposited by oxygen ion beam assisted RF sputtering on glass substrates. The influence of the oxygen flow ratio (0–100%) on the films’ optoelectronic properties was investigated. In our experimental conditions, all the films are crystallized in the cubic NiO phase. However, their crystallinity and mean grain size decreases with increasing oxygen flow ratios. Meanwhile, the films’ conductivity improves from 9.1 to 25.4 S·cm−1. This is due to the fact that the nickel vacancies along with hole carriers can be introduced into NiO films when they are deposited under higher oxygen flow ratio conditions. Thus, the O-rich environment is beneficial in enhancing the films’ carrier concentrations. In addition, with an increasing oxygen flow ratio, the film’s transmittance degrades. The direct optical band gap of Ni1−xO films declines slightly from 3.99 to 3.95 eV, with the oxygen flow ratio increasing from 0% to 100%.
ISSN:2079-6412