Raman scattering based strategies for quality control and process monitoring in electrodeposited CuIn(S,Se)₂ solar cell technologies

Abstract

This work reports the use of strategies based on Raman scattering for process monitoring of electrodeposited based S rich CuIn(S,Se)2 solar cells. Main vibrational modes in the Raman spectra are sensitive to features related to the crystalline quality, chemical composition and presence of secondary phases in the chalcopyrite layers, being all these features relevant for the optoelectronic properties of the final devices. Ex-situ and in-situ measurements during the electrochemical step allow the direct assessment on the formation of Se rich secondary phases which are related to the stoichiometry of the grown precursors. The analysis of the relative intensity of the spectral contribution from these phases allows early detection of deviations of precursor stoichiometry in relation to the optimum composition range in terms of solar cell efficiency. The applicability of the technique for the in-situ monitoring of the electrodeposition process is also discussed