Transport of majority and minority carriers in 2-µm-diameter Pt-GaAs schottky barriers

An experimental study of small area (2-µm-diameter) Pt-GaAs Schottky barrier diodes has been made, by using a wafer chip with a matrix of these diodes lying within approximately a minority carrier diffusion length of one another. Using one diode as collector and another as emitter, transistor measurements indicated that the dominant contribution to the current is the majority-carrier thermiconic field emission current for large forward-bias voltage ( V), whereas the smaller forward-bias ( V) recombination in the space-charge region was most important. The minority carrier injection ratio is measurable only for large forward-bias voltages, decreasing from ≃ 10^-2to 10^-5as VEBincreases from 0.5 to 1.0 V. The minority carrier diffusion length was measured to be µm. These results are of considerable significance for the understanding and optimization of the performance of these devices as classical detectors and mixers.