Lanthanum-modified lead zirconate titanate (PLZT) ceramics were obtained with high transmittance in the visible range by a combination of an inexpensive chemical processing and hot pressing. Optical, microstructural, pyroelectric, ferroelectric and dielectric properties characterized in this study attested the applicability of the employed method in the production of PLZT transparent ferroelectric ceramics. In fact, the corresponding analyzed physical parameters are in very good agreement with those obtained in samples traditionally prepared by other methods. Furthermore, due to high sample quality, a phenomenological analysis of the PLZT 10/65/35 relaxor features was performed in these ceramics

This paper reports on the formation of film structures and the highly improved photovoltaic output current of the lead lanthanum zirconate titanate (PLZT) employed. The photovoltaic effect of ferroelectrics has the advantage of its simple mechanisms of non-bias applications which are indispensable for semiconductor p-n junctions. But the output current of PLZT bulk is too low for use as a device current source. The PLZT film structure exhibited μA output current upon light illumination. The photovoltaic current of the PLZT film was more than 102 times than that of bulk PLZT. These differences are due to the characteristics of the design of the film including the configuration of the electrode. The PLZT film also has the advantage of easy output control and suitability for use on Si. Results show that the photovoltaic effect of the ferroelectric film is useful as the current source for micro-electro-mechanical systems (MEMS).

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This paper reports on the formation of a new layered film stmcture and the highly improved photovoltaic output of the lead lanthanum zirconate titanate (PLZT) employed. The new structure design is described using a top transparent indium tin oxide (ITO) electrode. PLZT in the 4-pm thick film was formed by means of a molecular organic deposition (MOD) raw solution. While the photovoltaic current of the PLZT layered film structure was more than 10' times larger than that of bulk ceramic and single crystal structures, the photovoltaic effect per unit in the layered film structure was almost the same as that in bulk ceramics.There are several kinds of ferroelectric materials that exhibit photovoltaic effects under near-ultraviolet illumination'. The most outstanding advantage of the photovoltaic effect is its high output voltage over kV. This phenomenon of ferroelectrics is entirely different from that of the semiconductor p-n junction. This is because the photovoltaic effect occurs within the material and is considered to be an optical property of the material itself. Photovoltaic effect holds promise in the following areas; 1) high electrical output voltage over kV, 2) transducer from optical energy to electrical one, 3) wireless energy transfer and 4) sensing system for ultraviolet light. These characteristics are useful and applicable to micro-electro-mechanical systems (MEMS). PLZT has been only used in bulk condition, a layered PLZT film structure was prepared using a repeated film coating process in this report.. The thickness of film was 4 mm. The lower gray part of the PLZT film is SiO2. The SEM inspection confirmed that the film structure was homogeneous. The interface between the lower electrode and the PLZT was flat and smooth without voids or deficiencies. Figure 2 is an XRD profile of the PLZT film. The presence of a typical perovskite structure was confirmed. We note that e had almost the same value as bulk PLZT, so the insurance of the film is adequate for electrical properties. Figures 3(a) and @) show the photovoltaic voltage and current, respectively. Both the photovoltaic voltage and current had linear relationships with the illumination intensity. Photovoltaic voltage and current reached 0.8 V and 1.7 pA in the region of highest light intensity at 150 mW/cm'. Table 1 gives a comparison of PLZT in formed film and bulk condition'. The photovoltaic current of film per unit width was 2 orders higher than that of the bulk material. Since bulk PLZT exhibits high photovoltaic voltage over kV and small photovoltaic current around nA per cm' and mm of thickness, it is difficult, with few exceptions, to explore useful and practical applications. differences are due to the characteristics of a PLZT structure between bulk and film. Though Figure l(a) shows a SEM figure of surface and @) a crossed sectional figure of formed film. These References 1, B.I.Shunan and V.M.Fridkin, "The photovoltaic and photorefractive effects in noncentrosymmetric materials", Gordon and Breach Sci.

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