Interpretation ofα-Values inp−nJunction Transistors

By the measurement of five parameters in several $p-n$ junction transistors, viz., the conductivities and diffusion lengths of minority carriers in the emitter and base regions and the widths of the base regions, the current amplification factor $\alpha$ of the transistors has been computed from theory. Previous to this investigation two of the parameters associated with the thin $p$-layer had not been measured. The quantity $\alpha$ also was obtained independently by two alternate methods: (1) by measuring the collector-emitter current characteristic, and (2) by measuring the apparent quantum efficiency of the transistor as a two-electrode photocell with a floating base. The three determined values of $\alpha$ for each sample agree within the experimental error.