Testing for lifetime reliability

Determining the reliability of compound semiconductor photovoltaic cells, sub-assemblies and modules is critical to establish a robust product, as well as assuring customer confidence. First principles understanding of the failure mechanisms is important to pinpoint which lifetime tests are truly revealing. As no standard can comprehensively cover the range of product configurations, manufacturers design and perform tests on an ad-hoc basis to establish confidence in their products. Furthermore, operational differences between terrestrial and space applications vary greatly, although some overlap exists. Knowledge of failure mechanisms is crosscutting and provides important information on potential failure modes and tests to vet those concerns. This work discusses the advantages and limitations of several strife tests, as well as inherent issues with the current system for establishing both beginning of life and lifetime reliability. Data is presented to elucidate complexities in reliability testing using current protocols.