IN THIS PROJECT, THE TEAM WILL APPLY DIFFERENT ACCELERATED AGING METHODS TO UNENCAPSULATED SILICON HETEROJUNCTION (SHJ) CELLS AND ARCHITECTURES WITH POLYSILICON (POLY-SI) PASSIVATING CONTACTS (TOPCON). SAMPLES ARCHITECTURES WILL PARALLEL THOSE FOR WHICH DATA EXIST FROM ENCAPSULATED AGING STUDIES; PLANAR SAMPLES WILL VARY A SPECIFIC PARAMETER TO PROBE MATERIALS FAILURES (THE TCO CONDITIONS FOR THE SHJ CELLS; THE METAL PASTE FOR THE TOPCON CELLS). THIS COMBINATION WILL ALLOW US TO ASCERTAIN CELL CONTRIBUTIONS TO MODULE FAILURE (BY COMPARING UNENCAPSULATED AGING TO ENCAPSULATED AGING), AND USE TEST STRUCTURES TO PROBE HOW PROCESSING OF THE DEVICES AFFECTS THESE CELL-BASED DURABILITY ISSUES.