Annealing of thin-film cadmium telluride photovoltaics using holographically controlled laser processing
conference contributionposted on 2016-11-03, 13:41 authored by Nick Goffin, Fabiana Lisco, Gianfranco ClaudioGianfranco Claudio, John TyrerJohn Tyrer, Elliot WoolleyElliot Woolley
CdTe-based thin film solar cells currently represent one of the fastest growing PV technologies, with a superior combination of efficiency, energy payback time and lifecycle environmental impact. However, the current post-deposition annealing treatment is still an energy intensive step of the manufacturing process. A novel method is presented for annealing of CdTe using a high-power diode laser (35 W, 808 nm) for thermal post-processing, combined with holographic optical elements (HOE’s) for laser beam heat flow control. The advantage of a laser for annealing lies in its ability to selectively heat only the surface of the CdTe solar cell; improving energy efficiency, process speed and energy resilience. Heat transfer simulations were used to predict the effects of different laser irradiance profiles on the annealing process thermal cycle influence the experimental design and predict optimal laser irradiance profiles. Variations in power and process speed on as-deposited and MgCl2-treated close-space sublimated (CSS) CdTe samples have been performed. The results were characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Optical properties were analysed with a spectrophotometer and ellipsometric spectroscopy (SE). The laser annealing treatment was found to be effective in promoting Chlorine diffusion and improving the optical and morphological properties of CdTe thin film devices
- Mechanical, Electrical and Manufacturing Engineering
Published inEMRS 2016 Spring Meeting Energy Procedia
CitationGOFFIN, N.J. ...et al., 2016. Annealing of thin-film cadmium telluride photovoltaics using holographically controlled laser processing. Energy Procedia, 102 pp.70-79.
Publisher© The Authors. Published by Elsevier
- VoR (Version of Record)
Publisher statementThis work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
NotesThis paper was presented at the EMRS 2016 Spring Meeting, Lille, France, May 2-6th. This is an open access article under the CC BY-NC-ND license.