Au/polymer P2ClAn(H3BO3)/n-GaAs Schottky barrier diodes, where P2ClAn stands for poly(2-chloroaniline), have been fabricated. To fabricate Schottky diodes with polymer interface, n-type GaAs wafer was used. The P2ClAn polymer solution was applied on the front face of the n-GaAs wafer by a pipette. The P2ClAn emeraldine salt was chemically synthesized by using boric acid (H3BO3). Schottky diode parameters, such as ideality factor, barrier height and series resistance have been measured, as functions of hydrostatic pressure, using the current-voltage technique. The ideality factor values of Au/P2ClAn/n-GaAs Schottky barrier diodes have decreased from 3.38 to 3.01, the barrier height has increased from 0.653 to 0.731 eV at 0.36 kbar and series resistances were ranging from 14.95 to 14.69. The results obtained from I-V characteristics of Au/P2ClAn/n-GaAs Schottky barrier diodes show that pressure treatment improves the rectifying properties of the diodes. These diodes can be used as pressure-sensitive capacitors, due to pressure-dependence of diode parameters.