GAMMA-CHI INTERVALLEY TRANSFER IN SINGLE ALAS BARRIERS UNDER HYDROSTATIC-PRESSURE

We have investigated the contribution of GAMMA-X intervalley transfer to the tunneling current in single AlAs barrier heterostructures grown on a GaAs substrate by measuring I-V characteristics at low temperatu re and under hydrostatic pressure up to 9 kbar. The application of hyd rostatic pressure affects the contribution of the GAMMA-X transfer pro cess to the total tunneling current at a given bias voltage. Experimen tal results are compared with current-voltage characteristics calculat ed with a model taking into account the GAMMA-X transfer at heterointe rfaces. Only transfer processes involving the longitudinal X valley in AlAs are considered in the calculations. Very good agreement is found for low bias conditions at all pressures.