Fabrication of chemically stable hydrogen- and niobium-codoped ZnO transparent conductive films.

Bing Han,Xudong Meng,Yanfeng Wang,Junjie Li,Yajuan Guo,Binting Dai,Fu Yang,Jianmin Song,Weiye Song

doi:10.1039/c9ra01231a

Bing Han, Xudong Meng + Show 7 more

Open Access

https://doi.org/10.1039/c9ra01231a

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Journal: RSC advances	Publication Date: Jan 1, 2019
Citations: 6	License type: CC BY 3.0

Affiliation: University North, Hebei Agricultural University

Abstract

H- and Nb-doped ZnO (HNZO) thin films were fabricated on glass substrates with radio frequency magnetron sputtering. The effect of the flow rate of H2 has been investigated by analyzing the structural, optical, and electrical properties. The incorporation of H during the deposition of Nb-incorporated ZnO films significantly improved their crystallinity, conductivity, and transmittance. The crystallites of the HNZO films were preferentially oriented in the c-axis direction; the films possess high transmittance (approximately 85%) in the visible and near-infrared regions (400 to 1400 nm). The lowest room-temperature resistivity of the HNZO films was measured as 1.28 × 10−3 Ω cm. Such optical and electrical properties along with the remarkable chemical stability of the HNZO films make them a promising candidate for applications in solar cells.

Highlights

Thanks to their inherent characteristics such as high electrical conductivity and high optical transmittance in the visible region, transparent conducting oxide (TCO) lms have found many applications as transparent electrodes in solar cells, optoelectronic devices, at-panel displays, and light-emitting diodes.[1,2] Any further extensive application of indium tin oxide (ITO) lms, such as the most commonly used TCO material, is hindered by the fact that indium is rare, expensive, and toxic
An commercially available Al-doped ZnO lms (AZO) (1000 nm) lms with sheet resistance of 7.8 U,À1 were used as reference to compare the chemical durability with that of an optimal H- and Nb-doped ZnO (HNZO) lm that exhibited the best electrical and optical properties, both of these lms were etched at room temperature with diluted HCl (0.5%), and at 80 C with NaOH (5%) for different etching times
The intensity of the (002) re ection was found to initially decrease upon the introduction of H2, and to subsequently increase when the ow rate of H2 was increased to 1.2 sccm; for H2 ow rates beyond this value, the (002) orientation was less favored. This observation can be explained by taking the high-energy O2À ion bombardment of the Nb-doped ZnO (NZO) lm into account; that is, the ion bombardment damages the (002) planes more seriously than other loosely-packed planes such as (101)—the surface of the growing lm will have a large number of dangling bonds;[45,46] the growth of the crystallites that are normal to the (101) plane will continue relatively undisturbed, and they can serve as seeds for further growth;[45,46] the termination of the dangling bonds upon the incorporation of hydrogen enables the sputtered atoms to travel further

Summary

Introduction

Thanks to their inherent characteristics such as high electrical conductivity and high optical transmittance in the visible region, transparent conducting oxide (TCO) lms have found many applications as transparent electrodes in solar cells, optoelectronic devices, at-panel displays, and light-emitting diodes.[1,2] Any further extensive application of indium tin oxide (ITO) lms, such as the most commonly used TCO material, is hindered by the fact that indium is rare, expensive, and toxic. We report on the fabrication of H-and-Nb-codoped ZnO (HNZO) lms in an atmosphere of Ar and H2 with different hydrogen ow rates which allow for investigating the effect of hydrogen ux on structural, electrical, and optical properties of Nb-doped ZnO (NZO) lms. The chemical stability of the fabricated HNZO in diluted HCl and NaOH was investigated

Experimental

Results and discussion

Conclusion