UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2022-07-01 17:49

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Conference: Bucharest University Faculty of Physics 2019 Meeting


Section: Solid State Physics and Materials Science


Title:
Physical characterization of Dy and Cu co-doped ZnO thin films grown by radio-frequency magnetron sputtering


Authors:
Claudiu LOCOVEI (1,2), Diana COMAN (1), Adrian RADU (1), Lucian ION (1), Vlad A. ANTOHE (1,3), Nicoleta VASILE (1,4), Marilena COLT (1), Marina MANICA (1), Anca DUMITRU (1), Sorina IFTIMIE (1) and Stefan ANTOHE (1,5)


*
Affiliation:
1) University of Bucharest, Faculty of Physics, 077125, Magurele, Romania

2) National Institute of Materials Physics, 077125, Magurele, Romania

3) Universit├ę Catholique de Louvain (UC Louvain), Institute of Condensed Matter and Nanosciences (IMCN), B-1348, Louvain-la-Neuve, Belgium

4) National Institute for Laser, Plasma and Radiation Physics, 077125, Magurele, Romania

5) Academy of Romanian Scientists, 030167, Bucharest, Romania



E-mail
lcvclaudiu@yahoo.com


Keywords:
zinc oxide, dysprosium, poly(3-hexylthiophene-2.5-diyl), copper (II) phthalocyanine


Abstract:
The physical properties of dysprosium (Dy) and copper (Cu) co-doped zinc oxide (ZnO) thin films deposited by radio frequency magnetron sputtering (RF-magnetron sputtering) on glass and quartz substrates were investigated. As source was used a homemade target having 1% atomic percentage (at.) of Dy and 1% at. of Cu, respectively. From structural characterization was found that before the annealing treatment the samples are dominating amorphous. After thermal treatment under nitrogen flow, at 800oC they become textured showing a w├╝rtzite structure. The morphological analysis show a relatively flat surface for thin films and at specific deposition parameters clusters of different sizes were observed. Both structural and morphological properties were improved by thermal treatment in the above conditions. Optical transmission spectra indicated high transmittance values, larger than 75% in all cases. The optical band gap of fabricated samples was calculated using the dispersion equation for direct band gap semiconductors. In order to evaluate the electrical behavior of grown thin films, hybrid organic/inorganic heterojunctions were built, and their current-voltage (I-V) characteristics were acquired in dark, at room temperature. The organic semiconductors used were either poly(3-hexylthiophene-2.5-diyl) (P3HT) or copper (II) phthalocyanine (CuPc). The small observed electrical hysteresis may be caused by the reorganization of defects at the p-n interface or by the differences in dielectric constant.


Acknowledgement:
This work was partially financially supported by FPRD project no. 18/2018 financed by UEFISCDI Romania.