Determination of nonuniform diffusion length and electric field in semiconductors

A method is proposed that purports to measure the non-uniform diffusion length in the presence of an arbitrary electric field . A point source of carrier generation (as a model for an electron beam) scans across the sample in the thickness direction x while the induced currents are measured at two reverse-biased junctions sandwiching the sample. and can be deduced from the currents. If only one collecting junction is present, one of the two functions may be deduced provided that the other is known; in addition, the surface recombination velocity at the other boundary may be determined in the presence of arbitrary and . With additional scanning in the and directions, quasi three-dimensional mapping is possible.