A simple method for implementing the steady-state photoconductance technique for determining the minority-carrier lifetime of semiconductor materials is presented. Using a contactless instrument, the photoconductance is measured in a quasi-steady-state mode during a long, slow varying light pulse. This permits the use of simple electronics and light sources. Despite its simplicity, the technique is capable of determining very low minority carrier lifetimes and is applicable to a wide range of semiconductor materials. In addition, by analyzing this quasi-steady-state photoconductance as a function of incident light intensity, implicit current-voltage characteristic curves can be obtained for noncontacted silicon wafers and solar cell precursors in an expedient manner.

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The current-voltage characteristics of solar cells and photodiodes can be determined by measuring the open-circuit voltage as a function of a slowly varying light intensity. This article presents a detailed theoretical analysis and interpretation of such quasi-steady-state V oc measurements (QssV oc). The ability of this analysis to accurately obtain the true steady-state device characteristics even in the case of high lifetime, high resistivity silicon devices is demonstrated experimentally. The QssV oc technique can be used to determine the minority carrier lifetime, and the new generalized analysis is required to do this accurately. An important outcome is that solar cell and diode device characteristics can be obtained from measurements of either the photoconductance or the open-circuit voltage, even using transient techniques.

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The effectiveness of a method for analytically reducing the effect of trapping centers on photoconductance-based recombination lifetime measurements in silicon is examined. The correction method involves the use of a ''bias-light'' term to subtract out the underlying photoconductance due to the traps. The technique extends, by approximately an order of magnitude, the range of carrier densities over which reasonably accurate ͑within 30%͒ measurements of the recombination lifetime can be made. Guidelines for determining which bias-light intensity will produce the best correction for solar grade multicrystalline silicon wafers, and the range over which it is valid, are developed for several practical cases.

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