SYSTEM FOR MEASURING THE MINORITY-CARRIER LIFETIME IN THE BASE OF SILICON SOLAR-CELLS

We show the development of a computer based system for measuring the m inority carrier lifetime in the base of silicon solar cells. The syste m allows using two different techniques for such kind of measurements: The open circuit voltage decay (OCVD) and the surface voltage decay ( SVD). The equipment is based on internal cards for IBM-PC or compatibl e computers that work as an oscilloscope and as a function generator, in addition to a synchronization and signal conditioning circuit. The system is fully controlled by a ''C'' language program that optimizes the used of the instrument built in this way, and makes the analysis o f the measurement data by curve fitting techniques. We show typical re sults obtained with silicon solar cells made in our laboratories.