Experimental and Theoretical Investigation of the Barrier Pyroelectric Effect in a Quantum Paraelectric 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 (10K-130K), reverse bias voltage (up to -500 mV) and chopping frequency (4Hz-2000Hz). The pyroelectric coefficient is about 10^(-3) microC/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.