Temperature dependence of forward current-voltage characteristics in a GaAs PiN structure with near-fully compensated i-region under low and high injection conditions

The forward current-voltage characteristics (I-V) of a GaAs P⁺ PiNN⁺ diode with a near-fully compensated (|N_d - N_a| < 5 × 10¹¹ cm^-3) i-region were investigated theoretically and experimentally in current density range j = 10^-11 - 10^-1 A/cm² and at temperatures between 300 and 700 K. It is shown that in a j range of 1-100 mA/cm² the forward voltage drop V is linear with temperature up to 550-700 K, and that its temperature dependence dV dT is changing in the range of 3.6-2.3 mV/K when j changes from 1.5 to 100 mA/cm². The maximum temperature of the linear range, T_lim, and dV dT depend on the thickness of i-region W_i: at an applied j of 10 mA/cm², when W_i increases from 5 to 30 μm, T_lim decreases from 640 to 540 K, and dV dT increases from 2.6 to 2.8 mV/K. A physical model is suggested, which enables simulation of the I-V characteristics at different temperatures and current densities, with calculated I-V curves matching exactly the experimental data.