Metal sulfides semiconductors with technological application in the photovoltaic field were prepared by electrodeposition. In particular, we used the E-ALD (Electrochemical Atomic Layer Deposition) to grow CuS and Cu-Zn sulfides on Ag substrates. E-ALD is a layer by layer growth technique which allows for the production of films with dimensional and compositional control. This technique exploits the Under Potential Deposition (UPD) phenomenon, which is a limited surface reaction and results in the deposition of a single monolayer of an element. The alternating sequence of UPD of two different elements results in the growth of binary compounds, and, in a similar way ternary chalcogenides can be grown. With the aim of performing a chemical, morphological and structural characterization of the grown films, we carried out TEM (Transmission Electron Microscope) for morphological and compositional information and SXRD (Surface X-Ray Diffraction) for the structural information. SXRD measurements have been performed at the ID03 beamline of the ESRF synchrotron in Grenoble during the experiments SI-2051 and MA-1716. In particular, the experiment MA-1716 was an in-situ experiment and this allowed to investigate the growth mechanism of CuS thin films. The growth of the film was monitored by following the evolution of the Bragg peak and monitoring the presence of powder diffraction rings. No shifts of the Bragg peaks were observed during the film growth, indicating an homogeneous growth process since the first layers. The intensity of the Bragg peak is appreciable from the 15th deposition cycle, suggesting that the material crystallize with low symmetry and a large elementary cell. No shifts in the Bragg peak position are highlighted comparing CuS and Cu-Zn sulfides, suggesting a similar crystalline structure. Analysis of these data are still in progress but all the samples show a high crystallinity proposing E-ALD as method to grow structurally ordered thin films.
An In-Situ and Ex situ SXRD and TEM Microscopy Study of CuxSz and CuxZnySz Thin Films
F. Di Benedetto
2014
Abstract
Metal sulfides semiconductors with technological application in the photovoltaic field were prepared by electrodeposition. In particular, we used the E-ALD (Electrochemical Atomic Layer Deposition) to grow CuS and Cu-Zn sulfides on Ag substrates. E-ALD is a layer by layer growth technique which allows for the production of films with dimensional and compositional control. This technique exploits the Under Potential Deposition (UPD) phenomenon, which is a limited surface reaction and results in the deposition of a single monolayer of an element. The alternating sequence of UPD of two different elements results in the growth of binary compounds, and, in a similar way ternary chalcogenides can be grown. With the aim of performing a chemical, morphological and structural characterization of the grown films, we carried out TEM (Transmission Electron Microscope) for morphological and compositional information and SXRD (Surface X-Ray Diffraction) for the structural information. SXRD measurements have been performed at the ID03 beamline of the ESRF synchrotron in Grenoble during the experiments SI-2051 and MA-1716. In particular, the experiment MA-1716 was an in-situ experiment and this allowed to investigate the growth mechanism of CuS thin films. The growth of the film was monitored by following the evolution of the Bragg peak and monitoring the presence of powder diffraction rings. No shifts of the Bragg peaks were observed during the film growth, indicating an homogeneous growth process since the first layers. The intensity of the Bragg peak is appreciable from the 15th deposition cycle, suggesting that the material crystallize with low symmetry and a large elementary cell. No shifts in the Bragg peak position are highlighted comparing CuS and Cu-Zn sulfides, suggesting a similar crystalline structure. Analysis of these data are still in progress but all the samples show a high crystallinity proposing E-ALD as method to grow structurally ordered thin films.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
