Optical monitoring and control of three-stage coevaporated Cu(In1−xGax)Se2 by real-time spectroscopic ellipsometry
Real-time spectroscopic ellipsometry (RTSE) has been applied for in situ monitoring and control of thin-film copper-indium-gallium-diselenide, i.e., Cu(In1−xGax)Se2 (CIGS), deposition by high vacuum coevaporation in the three-stage process used for efficient photovoltaic devices. Initial studies have been performed on a ∼0.7-µm CIGS layer deposited on crystal silicon to minimize surface roughness and to develop an accurate structural/ optical model of the Cu-poor-to-Cu-rich and Cu-rich-to-Cu-poor transitions that define the ends of the second (II) and third (III) stages of growth, respectively.With a better understanding of the surface achieved through this model, correlations can be made between the surface state and the unprocessed RTSE data {ψ(t), Δ(t)}. During deposition in the solar cell configuration with 2- µm-thick CIGS on a Mo-coated glass substrate, indications of the Cu poor-to-rich and Cu rich-to-poor transitions appear clearly in {ψ(t), Δ(t)}, enabling direct control of stage II and III transitions. The transition times deduced optically are in good agreement with those identified from the film/substrate emissivity by tracking the substrate heater power. It is clear, however, that RTSE can provide higher sensitivity to these transitions and is, therefore, suitable for improved control of three-stage CIGS deposition.
Real‐time analysis of the microstructural evolution and optical properties of Cu(In,Ga)Se2 thin films as a function of Cu content
Thin films of Cu(In,Ga)Se2 with various copper contents were deposited by co‐evaporation onto thermally oxidized silicon substrates. Characterization by real‐time spectroscopic ellipsometry reveals clear similarities among the samples, as well as key variations with Cu content. Although all films exhibit a Volmer–Weber nucleation and similar fundamental critical point energies in the analysis of optical properties, Cu‐rich films exhibit enhanced coalescence, smoother surfaces, larger grain sizes, as well as a sub‐bandgap absorption which is absent in Cu‐poor films. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Concept design of solar cell satellite dish
Solar panels are devices that consist of solar cells that convert light into electricity. They are called solar on the Sun or “sol” because the Sun is the strongest light source that can be utilized. Solar panels are often called photovoltaic cells, photovoltaic can be interpreted as “light-electricity”. Solar cells or PV cells depend on the photovoltaic effect to absorb the Sun’s energy and cause currents to flow between two opposing charged layers. The purpose of this study is to analyze the satellite dish using solar panels, so this tool is a signal search tool that uses solar energy to run to carry out its functions. As we know that many places or areas that are still often experiencing power outages so that it can hamper and interfere with community activities. Therefore, this research wants to facilitate the public, especially the current generation who need electricity every day so that when there is a power outage, the satellite dish will utilize solar energy as its main source. This research uses a satellite dish as an intermediary to produce electrical energy with the help of solar energy and is collected into a high-voltage battery in the form of electricity, so that it becomes a source of electricity.