Improved Cleaning Process for Textured similar to 25 mu m Flexible Mono-Crystalline Silicon Heterojunction Solar Cells with Metal Backing

An improved cleaning process is developed to remove front surface contamination for single heterojunction solar cells on textured surfaces on similar to 25 mu m thick exfoliated, flexible mono-crystalline silicon. The process is very effective in cleaning metallic and organic residues, without introducing additional contamination or degrading the supporting back metal used for ultrathin substrate handling. Quantitative analysis of the Auger electron spectra shows significant potassium contamination reduction (similar to 0.89% atomic) using the new cleaning process. An open-circuit voltage enhancement of 22 mV and an absolute 1.5% increase in conversion efficiency are observed with the new cleaning procedure for the exfoliated thin solar cells. (C) 2014 The Electrochemical Society. All rights reserved.