Controlling the p-Type Conductivity and Composition Range for Bipolar Conduction in NixCd1- xO Alloys by Acceptor Doping

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)20000-20009
Journal / PublicationJournal of Physical Chemistry C
Volume124
Issue number37
Online published25 Aug 2020
Publication statusPublished - 17 Sep 2020

Abstract

Oxide-based transparent p-n homojunctions are desirable for the development of transparent electronics. However, most oxide semiconductors are intrinsically n-type and to achieve p-type wide-gap oxide is still challenging. Previously, we have demonstrated that alloying a high-mobility n-type material such as CdO with p-type NiO can provide an avenue for electronic band engineering and consequently achieve bipolar conductivity in the midalloy composition. In this study, we synthesized O-rich NixCd1-xO alloys (NixCd1-xO1+δ ) over the entire composition with Li and Cu doping using radio frequency (RF) magnetron sputtering at room temperature. We show that by Li and Cu doping the conductivity in the p-type regime of these alloys is improved, which also leads to a wider composition window for bipolar doping in NixCd1-xO. Specifically, by Li doping, the p-type alloy composition can be extended to x ≥ 0.3 so that the bipolar doping window is expanded to 0.30 ≤ x ≤ 0.52. Detailed measurements on electrical, structural, optical, and electronic properties suggest that Li is an effective acceptor, offering a promising way to improve the p-type conduction in Ni-rich NixCd1-xO alloys as well as to regulate the bipolar conductivity in this alloy system. A p-Ni0.7Cd0.3O:Li/n-Ni0.45Cd0.55O quasi-homojunction was fabricated and a rectification ratio ∼102 with an ideality factor of ∼2.9 was obtained. The demonstrated quasi-homojunction structure also showed >60% transmittance in the visible spectrum.

Research Area(s)

Citation Format(s)

Controlling the p-Type Conductivity and Composition Range for Bipolar Conduction in NixCd1- xO Alloys by Acceptor Doping. / Egbo, Kingsley O.; Liu, Chao Ping; Hossain, Mohammad K.; Ho, Chun Yuen; Kwok, Cheuk Gary; Shil, Sujit K.; Ezeh, Chioma V.; Wang, Ying; Yu, Kin Man.

In: Journal of Physical Chemistry C, Vol. 124, No. 37, 17.09.2020, p. 20000-20009.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review