Minority-carrier transport parameters in n-type silicon

Minority-carrier diffusion length L, lifetime tau , and diffusion coefficient D in n-type Si are measured at 296 K in the doping range from 10/sup 18/ cm/sup -3/ to 7*10/sup 19/ cm/sup -3/. The measurement is based on a lateral collection of carriers generated by a spatially uniform light. The distance between the illumination edge and the collection junction is defined by photolithography. This allows simultaneous and independent determination of all transport parameters in the same material. A self-consistency and accuracy check is provided by the relation L/sup 2/=D tau . Details of experimental procedures are described. Empirical best-fit relations for the three parameters are given. The extraction of lifetime and diffusion coefficient was done in the frequency domain, which allows for straightforward elimination of parasitic effects in the nanosecond and subnanosecond range.<
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