DEPTH PROFILE ANALYSIS OF THIN-FILM SOLAR-CELLS USING SNMS AND SIMS

SNMS (sputtered neutrals mass spectrometry) and SIMS (secondary ion ma ss spectrometry) are used for the depth profile analysis of thin film solar cells based on amorphous silicon. In order to enhance depth reso lution! model systems are analyzed only representing parts of the laye red system. Results concerning the TCO (transparent conducting oxide)/ p interface and the n/i interface are presented. To minimize matrix ef fects, SNMS is used when the sample consists of layers with different matrices. Examples are the TCO/p interface (where the transition lengt hs of the depth profiles are found to be sharper when ZnO is used as T CO compared to SnO2) and SnO2/ZnO interfaces in coated TCO layers (whe re a Sn contamination inside the ZnO layer is found depending on the p lasma pressure during the ZnO deposition). SIMS is used when the limit s of detection reached by SNMS are not sufficient. Examples are H dept h profiles in ZnO layers or P depth profiles near the n/i-interface.