We correlate photoconductivity with surface characterization in order to probe the influence of surface properties of Si(111) on carrier dynamics. Results on the clean (7×7) reconstructed surface indicate that carrier recombination at this surface is fast, with a surface recombination velocity measured to be ≥2×106 cm/s. This is consistent with the notion of midgap dangling bond states acting as effective recombination centers. Combining our results and the present understanding of the (7×7) electronic structure, we estimate the carrier capture cross section for dangling bonds to be ∼10−15 cm2. We also investigate the effect of processing and find that carrier dynamics is strongly influenced by trace impurities below the detection limit of conventional surface characterization techniques.
Si(111)(7×7) dangling bond contribution to surface recombination
J. W. P. Hsu, C. C. Bahr, A. vom Felde, S. W. Downey, G. S. Higashi, M. J. Cardillo; Si(111)(7×7) dangling bond contribution to surface recombination. J. Vac. Sci. Technol. A 1 July 1992; 10 (4): 985–989. https://doi.org/10.1116/1.577891
Download citation file: