Sensitivity analysis for the determination of recombination parameters in Si wafers using harmonic carrier generation

Abstract

The sensitivity of a contactless measurement procedure to determine the minority-carrier recombination parameters in Si wafers is analyzed. The measurement is based on the harmonic generation of excess carriers, whose time dependence is measured either by μ-wave reflection or free-carrier absorption. Both the measurement equipment and the model used to extract the surface recombination velocity and the bulk carrier lifetime are introduced and the sensitivity of the parameter fit procedure is examined. The results of this uncertainty analysis are applied to typical experimental situations, e.g., bulk minority carrier lifetime measurement of a monocrystalline wafer with equal surfaces or a bulk minority carrier lifetime mapping done on an as-grown multicrystalline Si wafer before it obtained saw damage removal. The method proves to be very useful, if the interpretation of the results is carefully done and an appropriate experiment is chosen to produce the best possible results.

Simplified evaluation method for light-biased effective lifetime measurements

“…3,20 For lightbiased current measurements such as light-biased short circuit decay ͑SCD͒ measurements the simplified method is less suitable because of a larger influence of higher order surface modes. 7 This work has been carried out within the framework of the Dutch NWO priority program ''Solar cells for the 21st century'' with financial support from ECN ͑Long-Term Energy Research Programme͒.…”

All-optical multiwavelength technique for the simultaneous measurement of bulk recombination lifetimes and front/rear surface recombination velocity in single crystal silicon samples

“…Variations of the surface recombination velocity, even at a very low injection level, have arisen in the recent past. [9][10][11] Of course, this variation can lead to misinterpretation of the experimental data if it is not taken into account in the theoretical model. On the other hand, this effect, if present, can be easily identified by looking at experimental data because the variation of S with the injection level should cause nonexponential behavior in the asymptotic part of the transient decay.…”

The determination of charge‐carrier lifetime in silicon

“…Contactless, noninvasive excess free charge-carrier absorption measurements can also be performed in the THz, infrared and optical frequency range. These methods will not be discussed here and the reader is referred to the literature [3][4][5]. Probably the most interesting PC method using contacts is the Elymat method using electrolyte contacts [6].…”