Assessing Transient Measurement Errors for High-Efficiency Silicon Solar Cells and Modules

High-efficiency silicon solar cells are well known to have high “capacitance,” in the sense of having a slow time response to changes in voltage or current. This is often seen during power measurements of cells or modules. This issue is increasingly important as high-efficiency cells such as p-type passivated-emitter rear contact (PERC) and n-type heterojunction cells become more common within the industry. A fundamental understanding of solar cell device physics is essential to evaluate the various test methods used to accurately measure device power output under transient conditions during flash testing. This paper offers a simple device physics framework that is sufficient to understand a wide variety of test conditions and evaluate test solutions for cell or module output power measurements.