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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:10 |
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Conference: Bucharest University Faculty of Physics 2021 Meeting
Section: Solid State Physics and Materials Science
Title:
EFFECT OF WORKING POWER AND THERMAL TREATMENT ON PHYSICAL PROPERTIES OF RF-SPUTTERED CdTe THIN FILMS FOR PHOTOVOLTAIC APPLICATIONS
Authors:
Ana-Maria RADUTA (1), Sorina IFTIMIE (1), Vlad A. ANTOHE (1,2), Claudiu LOCOVEI (1,3), Adrian RADU (1), Lucian ION (1), Stefan ANTOHE (1,4,*)
*
Affiliation:
1) University of Bucharest, Faculty of Physics, Bucharest-Magurele, 077125, Ilfov, Romania
2) Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain (UCL), B-1348 Louvain-la-Neuve, Belgium
3) National Institute of Materials Physics, 077125, Magurele, Romania
4) Academy of Romanian Scientists, Bucharest, 030167, Romania
E-mail
*Corresponding author: santohe@solid.fizica.unibuc.ro (Ș. Antohe)
Keywords:
CdTe thin films, AII-BVI semiconductors, RF magnetron-sputtering, thermal treatment, photovoltaic applications
Abstract:
Among the AII-BVI binary semiconducting compounds, CdTe is one of the most promising photovoltaic (PV) materials that can be used especially for applications in the field of thin film solar cells, recording conversion efficiencies of 21.5 %, as shown by the reports made by First Solar in February 2015 [1-3]. The aim of our work is to improve the quality of CdTe thin films, by using the rf-magnetron sputtering as a reliable deposition method, having the ability to control the deposition parameters more easily and for a complex study our films were deposited onto p-type Si substrate, at four different working powers (70W, 80W, 90W and 100W). The structural properties of fabricated samples were investigated by grazing incidence X-ray diffraction (GIXRD). It is already known that GIXRD experiments are not adapted to obtain quantitative information, and for this the microcrystalline properties of CdTe thin films were investigated by performing a profile analysis of (111) reflection in Bragg-Brentano theta-theta geometry. The topography of the surface of fabricated CdTe samples was analyzed by atomic force microscopy (AFM), in non-contact mode, using an A.P.E. Research equipment. Morphological investigations of CdTe thin films were performed by scanning electron microscopy (SEM). From the cross-section SEM images, the thicknesses of all the samples were examined. Perkin-Elmer Lambda 750 UV/VIS/NIR spectrophotometer was used to study the optical transmission and absorption spectroscopy of the films in the wavelength region 400-1800 nm, in air, at room temperature. Therefore, in order to investigate the effects of RF power variation on the structural, morphological and optical properties of rf-sputtered CdTe thin films we decided to subsequently subject these layers to a thermal treatment under nitrogen gas flow using a Nabertherm oven. In particular, the physical properties of all the rf-sputtered CdTe thin films were investigated before and after the thermal treatment. The results obtained are promising and the related work deserves consideration in the future and in this sense our attention will be focused on the electrical characterization of the films.
References:
[1] Study of CdTe/ZnTe composite absorbing layer deposited by pulsed laser deposition for CdS/CdTe solar cell, He S, Lu H, Li B, Zhang J, Zeng G, Wu L, Li W, Wang W, Feng L, Mater Sci Semicond Process, (2017), 67:41–45.
[2] First solar raises bar for CdTe with 21.5 % efficiency record, Clover I, Avaible online: https://www.pv-magazine.com/news/details/beitrag/first-solar-raises-bar-for-cdte-with-215 efficiency-record_1000018069/#ixzz3faM4fEOOI, (2015).
[3] A novel CdTe ink-assisted direct synthesis of CdTe thin films for the solution-processed CdTe solar cells, Md. Ferdous Rahman, Jaker Hossain, abdul Kuddus, Samia Tabassum, Mirza H.K. Rubel, Md. Mahbudor Rahman, Yuma Moriya, Hajime Shirai and Abu Bakar Md. Ismail, Journal of Materials Science volume 55, (2020), pages 7715–7730.
Acknowledgement:
Support from the "Executive Unit for Financing Higher Education, Research, Development and Innovation" (UEFISCDI, Romania) through the grants: PN-III-P1-1.1-TE-2019-0868 (TE 115/2020) and PN-III-P1-1.1-TE-2019-0846 (TE 25/2020) is acknowledged.
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