Passivation Effect on ZnO Films by SF6 Plasma Treatment

Yumeng Xu,Zhongliang Qiao,Xin Gao,Baoxue Bo

doi:10.3390/cryst9050236

Yumeng Xu, Zhongliang Qiao + Show 2 more

Open Access

https://doi.org/10.3390/cryst9050236

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Journal: Crystals	Publication Date: May 5, 2019
Citations: 22	License type: CC BY 4.0

Affiliation: Changchun University of Science and Technology

Abstract

The passivation effects of SF6 plasma on zinc oxide (ZnO) films prepared by magnetron sputtering were researched. After the SF6 plasma passivation of ZnO films, the grain size increases, there is low surface roughness, and a small amount of Zn-F bonds are formed, resulting in the narrowing of band gap. The photoluminescence (PL) intensity of SF6-passivated ZnO films has a 120% increase compared to the untreated samples, and the reduction in defects can increase the resistivity and stability of ZnO films. ZnO films are used in the preparation of ZnO/p-Si heterojunction diodes. The results of the measurement of current voltage (J–V) show that the reverse current is reduced after SF6 plasma passivation, indicating an improvement in the electrical properties of ZnO films.

Highlights

Zinc oxide (ZnO) semiconductor materials have the advantage of large band gap (Eg = 3.36 eV), high electron mobility, high light transmittance, good chemical stability, and so on
The heterojunction structures based on zinc oxide (ZnO) films are widely used in solar cells [1,2,3], ultraviolet photodetectors [4,5], light emitting diodes [6], and field effect transistors [7,8]
The passivation of ZnO films is generally realized by doping them with Group III elements

Summary

Introduction

Many methods are used for the preparation of ZnO films, but the magnetron sputtering method is the most commonly used This method has the advantages of fast film deposition, good compactness, smooth surface, uniform film thickness distribution, and good controllability. Since it has a high surface state density caused by the defects of oxygen vacancies (oxygen dangling bonds) and zinc vacancies (zinc dangling bonds) in ZnO films [9,10], the result is a strong Fermi level pinning and high surface recombination rate, which will seriously affect the properties of the related devices [11,12,13]. Plasma treatment (oxygen ions, fluorine ions) is widely used because it can passivate the defects of ZnO films while improving the electrical conductivity.

Experiment

Measurement and Analysis

It as shows that the surface granule size increasesand by SF

The of ZnO

The electrical properties properties of of SF

Findings

Conclusions