Comparison of photoconductance- and photoluminescence-based lifetime measurement techniques

Accurate measurements of the injection-dependent excess carrier lifetime of silicon samples are essential for device optimization and controlling of solar cell processes. This excess carrier lifetime directly reflects the quality of the used semiconductor material and passivation quality. In addition, the ability to measure these injection-dependent lifetimes at different temperatures is of great benefit for advanced lifetime spectroscopy. In this contribution different techniques for measuring the excess carrier lifetime of silicon samples will be compared. In detail microwave-detected photoconductance decay (mu W-PCD), transient and quasi-steady-state photoconductance (TR-PC and QSS-PC), and quasi-steady-state photoluminescence (QSS-PL) will be investigated. Special features and limitations of each technique will be presented and analyzed in detail using silicon samples covering an excess carrier lifetime range from several milliseconds to a few microseconds.