Numerical analysis of a PbTiO/sub 3/ ferroelectric thin-film infrared optical diode

A thin PbTiO/sub 3/-n-p/sup +/ silicon diode has been developed, in which the conductivity increases with the infrared light power. The infrared-sensitive part consists of PbTiO/sub 3/ ferroelectric thin film deposited by RF sputtering. The diode has smaller heat capacity compared with other conventional infrared sensors because the tunneling current is allowed through the PbTiO/sub 3/ layer so that the PbTiO/sub 3/ film thickness can be thinned. Numerical analysis of the operational mechanism, such as the effects of infrared light power on the depletion layer width, n-p/sup +/ junction voltage, surface depletion region voltage drop, and voltage drop across the thin PbTiO/sub 3/ film, are reported in detail. Furthermore, some experimental measurements, such as the effects of infrared light power on current-voltage (I-V) curves and the dielectric constant of PbTiO/sub 3/ film, are compared with the theoretical analysis.