Dependence of Ga-doped ZnO thin film properties on different sputtering process parameters: Substrate temperature, sputtering pressure and bias voltage

THIN SOLID FILMS

卷:586

Article

Castro, M. V.¹  Tavares, C. J.¹ 

[1] Univ Minho, Ctr Phys, P-4710057 Braga, Portugal

关键词: Thin films;    Transparent conducting oxide;    Gallium-doped zinc oxide;    Sputtering;    Electrical properties;    Pressure;    Bias voltage;    Substrate temperature;   

DOI  :  10.1016/j.tsf.2015.04.036

来源: Elsevier

【 摘 要 】

This paper reports on the effects of different sputtering deposition process parameters (substrate temperature, sputtering pressure and bias voltage) on the electrical, optical, structural and morphological properties of gallium-doped ZnO (ZnO: Ga) of -1 mu m thick. These highly transparent and conductive films were deposited on glass surfaces by d.c. pulsed magnetron sputtering from a GZO (ZnO(95.5): Ga2O3(4.5)) ceramic target in an argon atmosphere. X-ray diffraction experiments show that all films have a hexagonal wurtzite structure with the [001] preferred crystallographic direction, and the morphology of the films (obtained from scanning electron microscope analysis) is sensitive to the process parameters. All ZnO: Ga films have an average transmittance above 80% in the visible region, and the lowest electrical resistivity of 3.03 x 10(-4) Omega.cm was achieved for the sample submitted to the lowest bias voltage (-40 V), which corresponds to a carrier concentration and a carrier mobility of 6.99 x 10(20) cm(-3) and 29.49 cm(2) V-1 s(-1), respectively. A high substrate temperature, high sputtering pressure and low negative bias voltage (within the range of studied parameters) proved to be very promising on obtaining optimized ZnO: Ga films, ensuring suitable properties for application as transparent electrodes in photovoltaic cells. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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