Experimental and theoretical investigation of the pyroelectric effect of the p-n junction in a paraelectric non-polar semiconductor

We describe here the first comprehensive investigation of a pyroelectric response of a p-n junction in a non-polar paraelectric semiconductor. The pyroelectric effect is generated by the, temperature dependent, built-in electrical dipole moment. High quality PbTe p-n junctions have been prepared specifically for this experiment. The pyroelectric effect was excited by a continuous CO₂ laser beam, modulated by a mechanical chopper. The shape and amplitude of the periodic and single-pulse pyroelectric signals were studied as a function of temperature (10-130 K), reverse bias voltage (up to −500 mV) and chopping frequency (4-2000 Hz). The pyroelectric coefficient is ≈10⁻³ μC/cm²K in the temperature region 40-80 K. The developed theoretical model quantitatively describes all the experimental features of the observed pyroelectric effect. The time evolution of the temperature within the p-n junction was reconstructed.