Development of field effect radiation detectors for use in infrared sensing and imaging devices

A pyroelectric field effect device has been developed using surface charge, which compensates the net temperature-dependent dipole moment of a pyroelectric substrate, to modulate the conductivity of a semiconductor surface film. A tellurium semiconductor film, chosen to match the lattice structure of the ceramic pyroelectric substrate, lanthanum-doped lead zirconate titanate, was vapor deposited or sputtered onto both sides of the substrate to form a unique two-sided field effect device configuration. The most reliable deposition technique used in this study was dc cathodic sputter cleaning prior to vapor deposition. The theoretical model proposed in the study predicts a maximum field effect response to radiation with a low impedance between the two sides of the device. The noise model identifies noise sources originating from thermal fluctuations (Johnson-Nyquist noise) in the semiconductor film channel resistance and the drain-source load resistor, temperature fluctuations in the substrate, and recombination noise in the pyroelectric substrate-semiconductor interface.