Characterization of high-temperature PbTe p-n junctions prepared by thermal diffusion and by ion implantation

Two types of high-quality PbTe p-n junctions, prepared by thermal diffusion of In4Te3 gas [thermally diffused junction (TDJ)] and by ion implantation [implanted junction (IJ)] of indium (In-IJ) and zinc (Zn-IJ), have been characterized. Capacitance-voltage and current-voltage characteristics have been measured over a temperature range from similar to 10 to similar to 180 K. The saturation current density J(0) in both diode types was similar to 10(-5) A/cm(2) at 80 K, while at 180 K, J(0)similar to 10(-1) A/cm(2) in TDJ and similar to 1 A/cm(2) in both IJ diodes. At 80 K, the reverse current started to increase markedly at a bias of similar to 400 mV for TDJ and at similar to 550 mV for IJ. The ideality factor was about 1.5-2 for both diode types at 80 K. Both diode types were linearly graded. The height of the junction barrier, the concentration and the concentration gradient of the impurities, and the temperature dependence of the static dielectric constant have been determined. The zero-bias resistance times area product (R(0)A(e)) at 80 K is 850 Omega cm(2) for TDJ, 250 Omega cm(2) for In-IJ, and similar to 80 Omega cm(2) for Zn-IJ, while at 180 K, R(0)A(e)similar to 0.38 Omega cm(2) for TDJ and similar to 0.1 Omega cm(2) for both IJ diodes. The estimated detectivity is D-*similar to 10(11) cm Hz(1/2)/W at T=80 K, determined mainly by background radiation, while at T=180 K, D-* decreases to 5x10(9)-10(10) cm Hz(1/2)/W and is determined by the Johnson noise. (c) 2008 American Institute of Physics.