{"title":"Pressure and Thickness Dependence of Physical Properties of ZnO:Ga Thin Films by Radio Frequency Magnetron Sputtering","authors":"Fang-Hsing Wang, Hua-Tz Tzeng","doi":"10.35745/afm2022v02.02.0005","DOIUrl":null,"url":null,"abstract":"Indium-free transparent conducting oxide films have attracted extensive attention in the field of optoelectronics. Ga-doped ZnO (GZO) thin films are deposited by radio frequency magnetron sputtering on glass substrates at a temperature of 200 °C with ZnO:Ga2O3 (3 wt%). The structural, electrical, and optical properties of the GZO thin films were investigated in terms of deposition pressure and film thickness variations. X-ray diffraction analysis showed that all the prepared GZO films exhibited hexagonal wurtzite crystal structure with a (002) preferential orientation along the c-axis, regardless of pressure and thickness. The average visible transmittance (including the glass substrate) in a wavelength range of 400–700 nm decreased with increasing thickness but varied less with pressure. The highest average visible transmittance reached 88.4% at the thickness of 150 nm and the pressure of 5 mTorr. The optical band gap of the GZO films calculated using Tauc’s method was in the range of about 3.6–3.9 eV. The resistivity of GZO thin films decreased with decreasing deposition pressure and increasing film thickness, and the minimum resistivity obtained at 5 mTorr and 1000 nm was 3.36 × 10-4 Ω-cm. The maximum figure of merit (FOM) of 3.09 × 10-2 Ω-1 was achieved at 5 mTorr and 1000 nm. The superior optical and electrical properties and high FOM show that the prepared GZO thin films are suitable for transparent conducting films and optoelectronic devices.","PeriodicalId":14985,"journal":{"name":"Journal of Applied Biomaterials & Functional Materials","volume":null,"pages":null},"PeriodicalIF":3.1000,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Biomaterials & Functional Materials","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.35745/afm2022v02.02.0005","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Indium-free transparent conducting oxide films have attracted extensive attention in the field of optoelectronics. Ga-doped ZnO (GZO) thin films are deposited by radio frequency magnetron sputtering on glass substrates at a temperature of 200 °C with ZnO:Ga2O3 (3 wt%). The structural, electrical, and optical properties of the GZO thin films were investigated in terms of deposition pressure and film thickness variations. X-ray diffraction analysis showed that all the prepared GZO films exhibited hexagonal wurtzite crystal structure with a (002) preferential orientation along the c-axis, regardless of pressure and thickness. The average visible transmittance (including the glass substrate) in a wavelength range of 400–700 nm decreased with increasing thickness but varied less with pressure. The highest average visible transmittance reached 88.4% at the thickness of 150 nm and the pressure of 5 mTorr. The optical band gap of the GZO films calculated using Tauc’s method was in the range of about 3.6–3.9 eV. The resistivity of GZO thin films decreased with decreasing deposition pressure and increasing film thickness, and the minimum resistivity obtained at 5 mTorr and 1000 nm was 3.36 × 10-4 Ω-cm. The maximum figure of merit (FOM) of 3.09 × 10-2 Ω-1 was achieved at 5 mTorr and 1000 nm. The superior optical and electrical properties and high FOM show that the prepared GZO thin films are suitable for transparent conducting films and optoelectronic devices.
期刊介绍:
The Journal of Applied Biomaterials & Functional Materials (JABFM) is an open access, peer-reviewed, international journal considering the publication of original contributions, reviews and editorials dealing with clinical and laboratory investigations in the fast growing field of biomaterial sciences and functional materials.
The areas covered by the journal will include:
• Biomaterials / Materials for biomedical applications
• Functional materials
• Hybrid and composite materials
• Soft materials
• Hydrogels
• Nanomaterials
• Gene delivery
• Nonodevices
• Metamaterials
• Active coatings
• Surface functionalization
• Tissue engineering
• Cell delivery/cell encapsulation systems
• 3D printing materials
• Material characterization
• Biomechanics