New approach for an industrial low-temperature roll-to-roll CI(G)Se hybrid sputter coevaporation deposition process

A new industrial approach for the production of CuInSe2 (CISe) absorber layers in a roll-to-roll process is described. This process is used by Sunplugged GmbH and combines magnetron sputtering with thermal coevaporation. A CISe-based device with a conversion efficiency of more than 10% has been fabricated from absorbers grown on polyimide at low temperature. The characteristic properties of a copper-poor ([Cu]/[In]=0.73) CISe layer, deposited by Sunplugged's industrial process, are compared to those of a state-of-the-art, more copper-rich ([Cu]/[In]=0.93) layer, grown in a molecular beam epitaxy system at Helmholtz-Zentrum Berlin. The presence of a so called vacancy-compound in low [Cu]/[In] CISe devices exhibiting an increased bandgap energy is visible by external quantum efficiency measurements, Raman scattering, and scaps simulations. (c) 2020 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1116/1.5142830