In this study CZTS thin films were fabricated by a two-stage process that sputter deposition of metallic Cu, Zn, and Sn on Mo coated glass substrates and annealing process at 500 °C using various short dwell times (4, 8, and 12 min) using... more
In this study CZTS thin films were fabricated by a two-stage process that sputter deposition of metallic Cu, Zn, and Sn on Mo coated glass substrates and annealing process at 500 °C using various short dwell times (4, 8, and 12 min) using Rapid Thermal Processing (RTP) approach. The X-ray diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and photoluminescence were employed to characterize the CZTS samples synthesized employing different sulfurization times. It was observed that all CZTS thin films showed Cu-poor and Zn-rich composition according to EDX results. XRD patterns displayed formation of kesterite CZTS and CuS secondary phases. Raman spectra of the films justified formation of kesterite CZTS phase for all CZTS thin films and formation of CTS phase, which is difficult to distinguish by XRD pattern of the films for CZTS-8 and CZTS-12 samples. SEM images of the films displayed dense, void-free, and inhomogeneous surface structure regardless of the sulfurization time. The optical band gap of the films as determined by photoluminescence was found to be about 1.36-1.37 eV.
In this study CZTSe thin film were synthesized by a two-stage process that included sequential sputter deposition of Cu and Sn layers forming a Cu/Sn structure, pre-annealing the Cu/Sn structure at 200-380°C for some of the samples,... more
In this study CZTSe thin film were synthesized by a two-stage process that included sequential sputter deposition of Cu and Sn layers forming a Cu/Sn structure, pre-annealing the Cu/Sn structure at 200-380°C for some of the samples, sputtering of additional Zn and Cu over the Cu/Sn structure, evaporation of a Se cap forming a Cu/Sn/ Zn/Cu/Se precursor film, and exposing the precursor film to high temperature annealing treatment at 550°C for 15 min to form the compound. The results of the characterization carried out on the compound layers revealed that the phase content, composition and microstructure of these layers changed noticeably depending on whether or not a pre-annealing step was utilized. Although XRD studies suggested presence of secondary phases, especially in the non-pre-annealed samples, the data was dominated by kesterite CZTSe phase reflections. Raman spectra of the films verified the formation of kesterite CZTSe structure and some other phases, which were determined to be SnSe 2 and possibly ZnSe. SEM micrographs showed denser structure in the pre-annealed samples.
View the article online for updates and enhancements. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and... more
View the article online for updates and enhancements. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
The current work describes a spectroscopic method for determining the electron temperature and electron density in an electron beam generator using argon spectral lines based on a collisional radiative model. Neutral and first-ionized Ar... more
The current work describes a spectroscopic method for determining the electron temperature and electron density in an electron beam generator using argon spectral lines based on a collisional radiative model. Neutral and first-ionized Ar lines emitted from the electron beam generator are studied experimentally. A collisional radiative code was developed to simulate the Ar (I) and Ar (II) spectral emission and to compare the results with the experimental data for electron density and temperature determination. Ar lines and excited level densities were calculated by solving rate equations using the Gauss elimination method. The argon spectrum is recorded experimentally by superposing two discharges, namely a low pressure DC glow discharge and a high current pulsed discharge. Spectral lines between 350 nm and 950 nm were recorded using an integrated signal technique on a chargecoupled device. Electron temperature is determined by the relative intensity ratio
In this study, we investigated the potential of multilayer TCO structures, specifically those made up of Indium Tin Oxide (ITO) and Indium Zinc Oxide (IZO), for crystalline silicon heterojunction solar cells (SHJ). We used the... more
In this study, we investigated the potential of multilayer TCO structures, specifically those made up of Indium Tin Oxide (ITO) and Indium Zinc Oxide (IZO), for crystalline silicon heterojunction solar cells (SHJ). We used the radiofrequency (RF) magnetron sputtering method to deposit various thin-film structures under various deposition temperatures and evaluated their electrical, optical, and morphological properties. The objective was to obtain films with lower sheet resistances and higher transmittances than those of single-layer thin films. Our results show that the ITO/IZO/ITO/IZO/ITO multilayer film structure deposited at 200 °C achieves the best sheet resistance of 18.5 Ohm/sq and a high optical transmittance of over 90% at a 550 nm wavelength. This indicates that multilayer TCO structures have the potential to be more optically and electrically efficient, and that they can improve the performance of optoelectronic devices. Finally, a power conversion efficiency of 17.46% wa...
