3, I3N, Institute for Nanostructures, Nanomodelling and Nanofabrication, Aveiro, , Portugal
5, IMEC, Leuven, , Belgium
6, Hasselt University, Hasselt, , Belgium
1, INL, Braga, , Portugal
2, Instituto Superior de Engenharia do Porto/ IPP, Porto, , Portugal
It is well known that one way of creating an environmentally friendly energy production momentum, which allows mitigating the effects of global warming, is closely linked to the commercial relevance of renewable energy production systems. Photovoltaic (PV) energy can play an important role in this field. Currently dominated by technology based on Si this technology has some drawbacks that prevent a greater market presence. High energy payback time and low industrial production rate, among others, are constrains to a higher PV share in the energy production systems in most countries. Due to monolithic integration, lower energy processes and lower material demand, thin film technology presents good arguments to overcome Si technology. CIGS and CdTe based PV cells are currently the most powerful representatives of thin film technology on the market. However, the solar cells based on these materials present problems related to the scarcity and toxicity of some elements that compose them. Alternative materials are currently been studied, such like Cu2ZnSn(S,Se)4, to be applied as absorber layer in the solar cell structure. But due to its complexity and restricted growth conditions some difficulties are been encountered. These facts have prevented the production of devices with efficiencies compatible with their commercialization.
In this work we present a method to grow Sb2Se3 thin film which can be used as absorber layer in a solar cell structures. These films were grown on the top of different substrates such as soda-lime glass, Mo coated soda-lime glass and Si. The Sb-Se precursor’s films were deposited by RF magnetron sputtering and then annealed with an H2Se gas flow. Different annealing temperatures were tested and analyzed. This study also analyses the effects of the use of different substrates on properties of the film. Compositional and morphological analyzes are performed by Energy Dispersive Spectroscopy and Scanning Electron Microscopy, respectively. Two techniques are used to phase identification and structural characterization, namely, X-ray Diffraction and Raman Dispersion Spectroscopy. Special attention is taken to Raman scattering characterization conditions in order to avoid measurement artefacts. Many authors show results with Sb2O3 Raman modes identified as Sb2Se3. In the work we clearly differentiate these modes from each binary compound and show how to avoid the oxidation of Sb. Spectrophotometry is also performed in order to determine absorption coefficient and the band gap energy of the semiconductor.