Numerical analysis of a PbTiO3 ferroelectric thin-film infrared optical diode

A thin PbTiO₃-n-p⁺ silicon diode has been developed, in which the conductivity increases with the infrared light power. The infrared-sensitive part consists of PbTiO₃ 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 PbTiO₃ layer so that the PbTiO₃ 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⁺ junction voltage, surface depletion region voltage drop, and voltage drop across the thin PbTiO₃ 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 PbTiO₃ film, are compared with the theoretical analysis